Abstract
An increasing amount of research regarding the correlates and consequences of organizational politics has been conducted in recent years as internal politics have proven to be quite pervasive in the private as well as the public sector jobs (Zettler & Lang, 2015). In recent years, research on organizational politicking has focused on the construct of political skill and how it can predict job performance in organizations (Ferris, Treadway, Brouer, & Munyon, 2012). Political skill can be briefly defined as a comprehensive pattern of “social competencies, with cognitive, affective, and behavioral manifestations” (Ferris et al., 2007, p. 291). Examples of political skill manifestations include networking with others, influencing others, and perceiving close attention to other’s non-verbal behaviors (Ferris et al., 2005). Thus, political skill can help perform essential job functions related to organizational goals and researchers have become increasingly interested in measuring and validating the political skill construct (Ferris et al., 2012). The Political Skill Inventory (PSI) is the most frequently used measure for assessing political skill as it is currently defined as a construct (Ferris et al., 2012; Zettler & Lang, 2015). As the PSI is the most frequently used measure of political skill as a construct, a reliability generalization of the scale was conducted to examine the variability of reliability coefficients in studies that used the PSI.
For the past decade, the political skill construct has received promising empirical support, generating increased attention by both researchers and practitioners, thus advancing the understanding of organizational behavior. More specifically, the political skill construct has received an increasing amount of attention from organizations in recent years because of the generally strong relationship measures political skills have with job performance across a variety of industries (e.g., Blickle, Ferris, et al., 2011; Ferris et al., 2007; Zettler & Lang, 2015; etc.). The main explanation for the general success of political skill in predicting job performance is largely based on the reasoning that individual employees with high levels of political skill are able to quickly identify and understand the subtle and hidden intentions and needs of their organization, co-workers, supervisors, and customers and also possess the competence to strategically modify their own behavior to influence their workplace environment to their advantage (Zettler & Lang, 2015). Previous research has also suggested that those with political skill improve their own performance by getting colleagues to assist them, assertively controlling negotiations and sales, and enhancing social networks that help them perform better (i.e., back-up staff and technical equipment; Zettler & Lang, 2015). In support of these findings, many studies (e.g., Blickle, Ferris et al., 2011; Ferris et al., 2007) including a meta-analysis (Being, Davison, Minor, Novicevic, & Frink, 2011) have all found a significant positive correlation between political skill and job performance across a number of different job types (Bing, Davison, Minor, Novicevic, & Frink, 2011). The primary objective of the present research is to investigate the typical magnitude and variabilities of reliability coefficient estimates reported across existing studies that administered the PSI—one of the most widely used measures of the political skill construct.
Political skill has been broadly defined as “the ability to effectively understand others at work, and to use such knowledge to influence others to act in ways that enhance one’s personal or organizational objectives” (Ahearn, Ferris, Hochwarter, Douglas, & Ammeter, 2004, p. 311). As a result, political skill involves the combination of social astuteness with the ability to adjust behavior to different situations to achieve personal or organizational goals using a manner that is perceived as sincere, inspires trust and motivation, and influences the responses of others (Ferris et al., 2005). More specifically, effective communication, friendships, network building, alliances, and coalition building are critical for individuals to navigate the politics of organizations to effectively achieve desired outcomes and represent an important aspect of political skill in the organizational politics literature (Ahearn et al., 2004; Ferris et al., 1999; Pfeffer, 1992). The other major aspect of political skill represented in the organizational politics literature is genuineness and the appearance of trustworthiness (Ferris et al., 2005). More specifically, the ability to maintain the appearance of sincerity allows politically skilled individuals to achieve a high level of interpersonal influence with individuals at work because they are able to inspire trust that motivates others to assist them with achieving and providing resources for their organizational or personal goals (Ahearn et al., 2004). Thus, the four primary dimensions of the political skill construct reflected in the organizational politics literature are social astuteness, interpersonal influence, networking ability, and apparent sincerity. The social astuteness dimension refers to the ability to accurately perceive as well as comprehend social situations and interpersonal interactions while the apparent sincerity dimension refers to the individual ability to be perceived by others as being honest, authentic, sincere, genuine, and possessing no ulterior motives (Ferris et al., 2005; Pfeffer, 1992). The interpersonal influence dimension involves the ability to appropriately adapt and adjust behavior to each situation to achieve a desired response or outcome, and the networking ability dimension refers to the capability or capacity to easily develop friendships and create strong beneficial alliances and coalitions to create and take advantage of opportunities (Ferris et al., 2005; Pfeffer, 1992).
The first measure that was developed to assess the political skill construct was the unidimensional, six-item PSI scale (Ferris et al., 1999). Although the unidimensional six-item PSI (Ferris et al., 1999) had acceptable psychometric properties, it was created for the primary purposes of preliminary construct exploration (Ferris et al., 2005). As a result, the six-item scale attempted to measure the political skill construct by examining two primary dimensions that were theoretically related to the construct: social astuteness and interpersonal influence (Ahearn et al., 2004; Ferris et al., 1999; Ferris et al., 2005). However, the original six-item PSI measure (Ferris et al., 1999) addressed the social astuteness and interpersonal influence dimensions of the political skill construct without separating the two dimensions into independent factors. The original six-item PSI did not include items for the purposes of assessing the networking ability and apparent sincerity dimensions of the political skill construct reflected in the organizational politics literature (Ahearn et al., 2004; Ferris et al., 2005).
Although the original unidimensional six-item version of the PSI (Ferris et al., 1999) provided initial construct evidence supporting the existence of the underlined latent political skill construct, the call for a more comprehensive, content-valid measure that adequately assessed each of the four primary dimensions of political skill theorized by organizational politicking literature led to the development of the full 18-item PSI (Ferris et al., 2005). To maximize the content validity of the 18-item PSI (Ferris et al., 2005), a pool of 40 items was generated with each item intended to generally asses the political skill construct and to reflect the specific dimensions associated with political skill (Ferris et al., 1999). The items included in the 18-item PSI scale (Ferris et al., 2005) were selected from the 40-item pool based on the results from item analyses in which only the items (a) with the highest item-to-total correlations, (b) not significantly correlated with the Social Desirability Scale total score, and (c) that did not cross-load highly onto more than one factor were retained. A factor analysis of the 18 items of the PSI captured the four-factor solution, with each of the four factors representing a theoretical dimension of the political skill construct: networking ability (six items), interpersonal influence (four items), social astuteness (five items), and apparent sincerity (three items). Of the six items included in the Ferris et al. (1999) PSI, only three were retained as part of the 18-item version of the measure: “I am able to make most people feel comfortable and at ease around me” (interpersonal influence), “it is easy for me to develop good rapport with most people” (interpersonal influence), and “I understand people very well” (social astuteness; Ferris et al., 2005).
Convergent and discriminant validity evidence for the two measures can be found in the literature. For example, Ferris et al. (2005) found evidence that total score of both the six-item and 18-item PSI measures were strongly correlated with self-monitoring, consciousness, trait anxiety, and social desirability which have each been previously hypothesized to be related to the political skill construct. However, Ferris et al. (2005) also found that the 18-item PSI was more related to the influence tactics of upward appeal and coalition in addition to being less related to the influence tactic of assertiveness than the six-item PSI, which indicates the 18-item PSI may more comprehensively capture the political skill construct. The small relationship between the six-item PSI with the influence tactics of appeal and coalition along with the significant relationship between the six-item PSI with assertiveness may likely demonstrate potential improvements of the 18-item PSI over the original six-item measure, as it has been hypothesized that those high in political skill will be more likely to engage in the more subtle and less direct influence tactics of appeal and coalition while avoiding more overt influence tactics such as assertiveness, which involves demanding ordering and checking up on others to exercise influence (Ferris et al., 2005; Kipins, Schmidt, & Wilkinson, 1980).
The full 18-item PSI (Ferris et al., 2005) is currently the most frequently implemented measure of the political skill construct in research being administered to over 76 samples in multiple languages with the six-item unidimensional version of the PSI (Ferris et al., 1999) being the next most frequently administered political skill measure. Thus, as the six-item PSI and 18-item PSI scales are the most frequently implemented and empirically validated measures of the political skill construct found in existing research, both versions of the scale were included in the current study to determine the reliability estimates of each. However, due to the substantial body of evidence indicating adequate psychometric properties and the inclusion of all four dimensions reflecting the political skill construct in the 18-item PSI Ferris et al. (2005) scale, the reliability coefficients obtained from the 18-item PSI represent the primary focus of this generalization study. Thus, the reliability coefficients obtained from the 18-item Ferris et al. (2005) PSI are reported separately in the results from the reliability coefficients obtained from the unidimensional six-item Ferris et al. (1999) PSI. Among the samples that were included in this reliability generalization study that administered the 18-item PSI, reliability coefficients were often reported separately for each of the four dimensions in addition to the reliability coefficient for the entire PSI scale. Reliability estimates reported for the four dimensions were only obtained from samples that administered the 18-item version of the PSI as the six-item PSI measure is unidimensional and does not distinguish between any of the four PSI dimensions.
Reliability
Reliability refers to “the results obtained with an evaluation instrument and not to the instrument itself” (Gronlund & Linn, 1990, p. 78). The psychometric literature is clear that reliability is based on scores gathered from a measurement scale and will vary from sample to sample (Thompson & Vacha-Haase, 2000; Vacha-Haase, Henson, & Caruso, 2002; Vacha-Haase, Kogan, & Thompson, 2000). Thus, it is informative to investigate how the reliability of a measure varies according to sample characteristics, administration procedures, and so on.
The reliability of the test for a population can be defined as the ratio of true score variance to observed score variance, or as the squared correlation between true and observed scores (Lord, 1959; Nunnally, 1978). In actual practice, however, true scores can never be determined; therefore, the reliability is typically estimated by coefficients of internal consistency, test–retest, alternate forms, and other reliability methods mentioned in the psychometric literature (Dimitrov, 2002; Vacha-Haase, 1998; Vacha et al., 2000). For this reliability generalization study, however, given the limited number of studies that reported other types of reliability, the internal consistency reliability coefficient of Cronbach’s alpha alone was investigated in this study. As Cronbach’s alpha will generally increase as the intercorrelations among test items increase and the intercorrelations of test items tend to increase when all of the test items measure the same underlying construct, higher values of alpha are generally thought to indicate that a particular set of test items measure a single construct. Although several researchers (e.g., Cronbach, 1951; Nunnally, 1978, etc.) have shown that alpha values can be considerably high even when the set of items measure multiple unrelated latent constructs, our use of alpha in this reliability generalization study of the PSI seems appropriate given researchers have generally agreed that alpha is most appropriately utilized when the items in a test measure a single construct (Nunnally, 1978).
Reliability Generalization
Reliability generalization (RG) reflects a meta-analytic approach to quantify reliability scores across samples and examine the variability of the reliability estimates (Thompson & Vacha-Haase, 2000; Vacha-Haase, 1998; Viswesvaran & Ones, 2000). Reliability coefficients are collected across studies to calculate central tendency and variability. Sample characteristics can be tabulated in an attempt to account for the variability in reliability estimates (e.g., Thompson & Vacha-Haase, 2000; Yin & Fan, 2000; etc.). In addition, the current reliability generalization study utilizes general linear modeling to provide indications of when the use of the PSI is more or less favorable in terms of expected measurement error. More specifically, sample gender distribution, the number of items included in the measure, sample population, language, geographic location, and the number of response options are all examined in the current study as potential factors that might influence the score reliability obtained from the PSI. Thus, the findings of the current study could likely serve as an additional source of information and reference for future practitioners and researchers in that it may shed light on potential contextual moderators that may lower (or raise) the reliability of the PSI measure depending on different sample and situational circumstances.
Factors That Influence Reliability
Number of Items
As mentioned previously, as the 18-item PSI (Ferris et al., 2005) and the six-item PSI (Ferris et al., 1999) are the most frequently implemented and empirically validated measures of the political skill construct, both versions of the PSI were included in the current study to determine the reliability estimates of each as well as potential contextual variables that may impact the overall scale reliability of each. Although implementing the shortened six-item version of the PSI may be practically appealing to many organizations and researchers due to the reduced time and cost involved during administration, many researchers have contended that the 18-item PSI more accurately reflects the theoretical definition of the political construct by explicitly including items for each of the four subdimensions. In terms of reliability, research has shown consistently that there is a tendency for the internal consistency of a measure to increase when the number of items increases as alpha is a function of the average interterm correlation and the number of items in a measure (Hellman, Fuqua, & Worley, 2006).
Number of Response Options
Given the high prevalence of Likert-type scales in organizational research, determining the optimal number of response options for participants to maximize internal consistency is an important consideration during the construction of such scales (Mattel & Jacoby, 1971, 1972). Early work on response format by Bendig (1954) provided evidence that the internal consistency reliability of a test may not be affected much by the number of alternatives provided in Likert-type scales. Providing many response options may not increase reliability if raters consistently utilize only a small proportion of them. In some instances, research has found that reducing the number of response options to an extreme degree can result in lowered estimates of reliability (Mattel & Jacoby, 1971, 1972). For example, Schmidt and Hunter (1998) found that the average correlation of items was significantly reduced when the response options were reduced from multiple to dichotomous response options. However, as all of the PSI measures included in the current reliability generalization study utilize response options from either 1 to 5 or 1 to 7 Likert-type scale, it seems unlikely that there would be a significant difference in the average internal consistency reliability estimates between the two.
Language
Increasing number of organizations are using personality assessment for selection purposes in international contexts (Bartram, 2008; Oswald, 2008). When measuring a construct for occupational assessment (e.g., as part of a job selection procedure), organizations will often use various adaptations of the same instrument to assess people from various countries and will then make direct comparisons between these people (Bartram, 2008; Oswald, 2008). This raises a need to compare the results of people who have completed an instrument in different countries or using different language versions (Bartram, 2008). The goals of translating a test are to preserve (a) translinguistic and (b) transcultural meaning of test items—so that candidates read and respond to equivalent measures (Daouk, Rust, & McDowall, 2005). However, this is not always possible as some items may sound stronger or weaker in a target language, and as a result, wording sometimes must be changed to reflect the same strength of the item in both language versions of a test (Bartram, 2008; Daouk et al., 2005). Thus, the measurement error of the test may differ across language versions of a measure due to differences in translation of items.
Geographic Location
In addition to language, cultural differences between the various geographic locations a test is administered in may lead to systematic differences in measurement error between samples from different geographic locations (Bartram, 2008; Daouk et al., 2005; Mushquash & Bova, 2007; Oswald, 2008). Specifically, decrements in reliability and validity may arise when a measurement instrument that has been developed in a particular culture is applied to other cultural groups for which it was not originally intended (Mushquash & Bova, 2007; Oswald, 2008). Thus, cultural differences between geographic locations regarding the targeted latent construct of political skill and its four subdimensions may lead to systematic differences in the measurement error of the PSI between samples from different geographic locations.
Sample Population
By knowing in which types of populations a measure generally has demonstrated low reliability, researchers and practitioners can make more informed decisions when evaluating test scores. Indeed, previous RG studies have found varying reliability coefficients for the same measure and subscales administered to different types of sample populations such as students and employees (e.g., Dimitrov, 2002; Hellman et al., 2006; Vacha-Haase, 1998; Vacha-Haase et al., 2000, etc.). As the PSI was designed to measure employee political skill in the workplace setting, determining if it has an acceptable reliability across samples consisting of all employees is an important contribution of the current RG study. In addition, the current study investigates if the PSI is more or less reliable when it is administered to employees in occupational settings compared with when it is administered to full- or part-time students in academic settings.
Sample Gender Distribution
Previous research has demonstrated the demographic composition of a sample can affect the internal consistency of a measure. For example, one investigation found that more homogeneous groups that were administered the Coppersmith Self-Esteem Inventory yielded higher reliability coefficients than heterogeneous samples (Lane, White, & Henson, 2002). One demographic variable that may be especially important to consider when administering an organizational measure to a sample is gender as previous research has indicated that differences in measurement error between countries and languages are smaller on average than differences in measurement error between males and females on international selection tests (Bartram, 2008; Oswald, 2008). For example, Oswald (2008) found there were significant gender differences in scoring and reliability between men and women participants in all but one of the 32 scales contained in the Occupational Personality Questionnaire Inventory (OPQ32i) that describe an individual’s preferred and typical behavior at work (Oswald, 2008). As a result of potential differences in measurement error based on gender, it is important to determine if there are systematic differences in internal consistency reliability estimates of PSI scores based on the gender composition of a sample (Bartram, 2008; Oswald, 2008).
Method
Following the methods suggested by Vacha-Haase (1998), reliability generalization was completed to (a) calculate the typical reliability of scores of a test across studies, (b) examine the amount of variability in reliability coefficients for the given test, and (c) identify the sources of variability in the reliability coefficients across studies. The keywords “Political Skill Inventory” were entered in a search using the “tests and measurements” search option in the PsycINFO database. From this initial search, we located 98 original journal articles that reportedly included the PSI as a measure in their study. For this study, of the 98 articles, we included only those that met the following criteria: (a) the study administered the PSI scale, (b) a reliability coefficient was reported in the study, (c) the reliability coefficient reported was from their own local sample (reliability coefficients cited from previous studies were excluded), and (d) the study was available in English. Of all of the studies in the original search list, only one was written in a language other than English (Marinho-Araujo, 2014), and as no translated version could be found, it was left out of our analyses. Two more studies were left out of the analysis because they used a sample of school-aged children 6 to 12 years of age and a modified version of the PSI (Lavi & Slone, 2011, 2012). The remaining 95 studies which met these four qualifications were included in the current reliability generalization study. In the 95 studies, there were reliability coefficients reported for 101 separate samples.
In addition, separate reliability coefficients were often reported separately for each of the four dimensions in addition to the reliability coefficient for the entire PSI scale. For example, Zettler and Lang (2015) reported reliability coefficients for the entire PSI, network ability, interpersonal influence, social astuteness, and apparent sincerity, and found that aside from the political skill dimensions of interpersonal influence and social astuteness, all internal consistency estimates were acceptable in their sample (α
Following the protocol outlined by previous reliability generalization studies (e.g., Vacha-Haase, 1998, Vacha-Haase et al., 2000), six features were included as predictor variables that may predict a significant amount of variability in the reliabilities reported across the studies. The predictor variables included in this study were the following: (a) the length of the PSI scale (full 18-item PSI scale coded as 0 and the Ferris et al., 1999, six-item unidimensional PSI scale coded as 1), (b) language in which PSI was administered (English coded as 1 and others as 0), (c) response format (seven-option response scale coded as 1 and five-option response scale as 0), (d) the gender mix of the sample (0%-25% males coded as 0, 25%-50% as 1, 50%-75% as 2, and 75%-100% as 3), (e) if the study included student or employee samples (all-student samples coded 1 and employee samples coded 0), and (f) geographic location of the sample (samples in the United States coded as 0, samples in Germany coded as 1, and samples in China, Taiwan, and Japan coded as 2).
Upon further examination, there were 101 samples in the 95 articles that reported reliability coefficients of the total PSI or at least one of the four subdimensions. Of the 101 samples included in the analysis, 77 samples reported overall scale reliability coefficient for the full 18-item PSI scale, which was analyzed as the overall scale reliability estimate of the PSI. The remaining samples either reported reliability coefficients of the shortened six-item Ferris et al. PSI measure or only reported reliability estimates for one or more of the PSI dimensions from the 18-item PSI without reporting the overall scale reliability and were not included in analyses of the overall scale reliability. Of the 77 samples that reported reliability coefficients of the full 18-item PSI, there was a total of 15,987 participants (with sample sizes varying from 25 to 558). In addition to reporting the weighted Cronbach’s alpha reliability coefficient of the full 18-item PSI, the weighted alpha reliability coefficients of each of the four dimensions of the PSI were also reported independently using the samples that reported separate reliability coefficients for the four dimensions. More specifically, of the samples that reported reliability coefficient estimates for one or more of the PSI dimensions, 27 samples reported a reliability coefficient for the networking ability dimension, 27 reported for the interpersonal influence dimension, 25 for the social astuteness dimension, and 25 for the apparent sincerity dimension. We summarize in the tables whenever there were over three reliability confidents reported for each of analysis. Thus, the tables in our results do not report the reliability coefficients for the four PSI dimensions unless there was a sufficient number of samples in each of the groups being compared. The source PSI reliability reports are designated with asterisks in our references.
Results
The weighted coefficient alpha internal consistency reliability estimate for the Ferris et al. (2005) 18-item PSI and each of the four PSI subdimensions are summarized in Table 1. Coefficient alpha internal consistency reliability estimates for the Ferris et al. (2005) 18-item and the Ferris et al. (1999) six-item PSI are summarized in Table 2, and the coefficient alpha internal consistency reliability estimates by response option type are summarized in Table 3. Estimates of coefficient alpha for samples administered English and non-English versions of the PSI are summarized in Table 4, and estimates of coefficient alpha by geographic location are summarized in Table 5. Table 6 compares estimates of coefficient alphas for all-student samples with employee samples. Finally, estimates of coefficient alpha by sample gender composition are summarized in Table 7. It should be noted that the four dimensions of the scale are only present in Tables 1, 3, and 4, as we did not include results of the analysis that were based on less than three reliability estimates.
Internal Consistency Reliability Estimate of the 18-Item PSI and the Four Dimensions.
Internal Consistency Reliability Estimate of the 18-Item PSI and Six-Item PSI.
Internal Consistency Reliability Estimate of the PSI by Response Scale Type.
Internal Consistency Reliability Estimate of the PSI by Language Version.
Internal Consistency Reliability Estimate of the Overall PSI by Geographic Location.
Internal Consistency Reliability Estimate of Overall PSI by Sample Population.
Internal Consistency Reliability Estimate of the PSI by Sample Gender Composition.
The sample size weighted mean and standard deviation was computed for each distribution analyzed. We also computed the unweighted mean and standard deviation for each distribution of reliability coefficients. As the unweighted mean and standard deviation do not weigh the reliability estimates by sample size of each study included in the analysis and each reliability coefficient is weighted the same, the sample size weighted mean gives the best estimate of the mean reliability while the unweighted mean helps ensure that the results of the analysis are not skewed by a few large samples (Viswesvaran, Ones, & Schmidt, 1996). In addition, the mean and standard deviation of the square root of the reliabilities were also calculated as the mean of the square root of the reliabilities differ slightly from the square root of the mean of the reliabilities. Thus, for each of the distributions included in our analysis, we reported (a) sample size weighted mean reliability estimates, (b) sample size weighted standard deviation estimates, (c) unweighted mean reliability estimates, (d) unweighted standard deviation estimates, (e) sample size weighted square root of the reliability mean, (f) sample size weighted standard deviation of the square root of reliabilities, (g) unweighted square root of the reliability mean, (h) unweighted standard deviation of the square root of the reliabilities, and (i) the sample size weighted (80%) confidence interval for the sample size weighted mean reliability estimate. Confidence intervals were calculated by multiplying the ratio of the weighted sample standard deviation (
The results from Table 1 indicate that the sample weighted coefficient alpha for the 18-item PSI scale across the samples included in the meta-analysis that reported an alpha coefficient for the entire 18-item scale was .89 (
The results from Table 2 indicate that the weighted reliability coefficient alpha for the shortened six-item PSI scale was .81 (
Results from Table 3 indicate that the sample weighted reliability coefficient alpha for samples that administered the full 18-item PSI using a five-option response option was .89 (
The results from Table 4 indicate that the sample weighted reliability coefficient alpha for the full 18-item PSI administered in English was .90 (
The results from Table 5 summarize the reliability coefficient estimates of the full 18-item PSI by geographic location. Results from a one-way ANOVA that was conducted using the geographic location as the independent variable and the weighted alpha reliability coefficient as the dependent variable indicated that the geographic location did not significantly impact the overall reliability of the PSI,
Results from Table 6 indicate that the sample weighted coefficient alpha estimate of the full 18-item PSI for all-student samples that were administered the PSI in academic settings was .89 (
Finally, Table 7 summarizes the overall reliability of the 18-item PSI by the sample gender composition. Results from a one-way ANOVA with sample gender composition as the independent variable and the weighted reliability coefficient of the overall 18-item PSI scale as the dependent variable indicated that the gender composition of the sample did not significantly affect the weighted reliability estimate of the 18-item PSI scale,
A six-factor ANOVA was subsequently conducted with PSI scale length, language administered, geographic location, response format, sample population type, and sample gender proportion as predictor variables and the sample weighted Cronbach’s alpha coefficient of the overall PSI scale as the dependent variable to test for the combined effects for the six predictors on the total PSI’s reliability. Results indicated that the six predictor variables significantly impacted the weighted reliability of the overall PSI scale,
Subsequently, four 5-factor ANOVA were conducted using the language of administration, geographic location, response format, sample population type, and sample gender proportion as predictor variables and the sample weighted reliability estimate of each of the four PSI subdimensions as the dependent variable to test for the combined effects of the five predictors on each of the four PSI subdimensions. Scale length was not included as a predictor in each in the analysis of the four PSI dimensions because only 18-item versions of the PSI reported independent reliability coefficients for each of the dimensions. For the networking ability dimension of the PSI, results indicated that the language of administration, geographic location, response option format, sample population type, and the sample gender composition accounted for a marginally significant amount of variance in the reliability coefficients,
For the interpersonal influence dimension of the PSI, results indicated that the five predictors accounted for a significant amount of variance in the reliability coefficients,
For the social astuteness dimension of the PSI, the five predictors accounted for a significant amount of variance in the reliability coefficients,
Finally, for the apparent sincerity dimension of the PSI, the five predictors did not account for a significant amount of variation in the reliability estimates,
Discussion
The primary objective of the present research was to utilize RG techniques to investigate the magnitude and variabilities of reliability estimates that were reported across existing studies using of the PSI developed by Ferris et al. (2005). Across the samples that used and reported reliability estimates for the full Ferris et al. (2005) PSI measure, the sample-weighted alpha coefficient of the 18-item PSI was .89 (
Contributions to Theory and Implications for Practice Regarding the Reliability of the PSI
Although the estimated reliability of the 18-item PSI and its dimensions seemed to be acceptable on average, results of the current study also indicated that the estimated reliability of the full 18-item PSI measure (Ferris et al., 2005) was significantly greater than the average weighted reliability estimate for the six-item unidimensional PSI scale (Ferris et al., 1999) as well as each of the four specific PSI subdimensions. Among the samples that were administered the shortened six-item version of the PSI (Ferris et al., 1999), the average weighted estimated alpha reliability coefficient was .81 (
Results of the current study also indicated that the estimated reliability of the full 18-item PSI measure (Ferris et al., 2005) was greater than the average weighted reliability estimate for each of the four PSI subdimensions (apparent sincerity, networking ability, interpersonal influence, and social astuteness). The length of the instrument used for measurement could be a possible explanation for the difference in reliability between the full PSI and specific PSI dimensions as the majority of the studies included in the analysis included a summing the four dimensions of into a single composite score. The relationship between reliability estimates and the number of items can be described as convex, with the reliability increasing rapidly as the number of items increases up to a certain point, but increases being relatively small after a certain amount of items. The measures included in the current analysis were long enough that the presence of additional items and the Spearman–Brown formula did not seem to make an appreciable difference in the overall reliability estimated for the four PSI subdimensions. An additional potential explanation for higher alpha coefficients for ratings of the overall PSI is related to the broad construct of political skill compared with the four PSI subdimensions that more narrowly defined facets of political skill. Indeed, previous research has found evidence that broader constructs are generally more reliably rated than more narrowly defined traits, supporting the possibility the overarching construct of political skill may be more easily identified across various types of behavioral manifestations than the four more narrowly defined dimensions of political skill (Ones & Viswesvaran, 1996; Viswesvaran & Ones, 2000). As a result, it seems possible that the findings of the current study reflect similar findings of previous research that the underlying general political skill construct may more reliability predict a wide range of organizational outcomes than any one of the four PSI subdimensions assessed independently. However, future research is needed to examine how overall scores of the full Ferris et al. (2005) 18-item PSI measure and scores of specific PSI subdimensions assessed independently are each related to various types of general and specific organizational outcomes.
Potential fluctuation of reliability coefficients was evident in the full 18-item PSI measure along three of the four dimensions. For the full Ferris et al. (2005) 18-item PSI measure, results indicated that sample type (e.g., all-student samples or employees), response style type (e.g., five-option or seven-option self-reported Likert-type scale), the gender makeup of the sample, the geographic location of the sample, and whether or not the PSI was administered in English or another language did not significantly affect the overall reliability of the PSI scale. However, as previously mentioned, results did indicate that samples that used the full 18-item PSI scale had significantly higher overall reliability coefficients than samples that used the shortened six-item version of the PSI scale.
Given the influence of score reliabilities on effect size (Hellman et al., 2006; Wilkinson & Task Force on Statistical Inference, 1999), the use of shorter PSI versions seems to clearly be a decision that should be made after careful consideration. Although shortened unidimensional scales of the PSI may seem to have acceptable psychometric properties, such scales were developed for the purposes of preliminary construct exploration of political skill, have suboptimal internal consistency, and often do not adequately measure each of the four political skill dimensions as well as the Ferris et al. (2005) full 18-item PSI measure (Ferris, Rogers, Blass, & Hochwarter, 2009). Thus, the Ferris et al. (2005) 18-item PSI should be preferred over the shortened Ferris et al. (1999) six-item unidimensional PSI scale.
Reliability of the Four PSI Dimensions
As far as the four dimensions of the PSI (networking ability, interpersonal influence, social astuteness, and apparent sincerity), results indicated that the language the measure is administered in may have an effect on the reliability coefficients of the networking ability, interpersonal influence, and social astuteness dimensions of the PSI. Specifically, our results indicated that the sample-weighted reliability coefficients of the networking ability, interpersonal influence, and social astuteness subdimensions of the PSI were significantly higher in samples that were administered English versions of the PSI compared with samples that were administered the PSI in a non-English language. It may be due to lack of standardization in the precise wording in the way the PSI is translated from English to other languages that affected the estimates. Previous research has found that translating certain items into different languages can pose a unique challenge to standardization as the verbatim translation of some words may have drastically different meanings in two languages and may result in the re-wording of some items in the translated version of the measure which may potentially affect item interpretation across languages (Bartram, 2008; Oswald, 2008). However, the average Cronbach’s alpha reliability estimate of the translated social astuteness subscale seemed to be adequate and the average overall reliability of translated non-English versions of the full PSI scale is not significantly different compared with the overall reliability of English versions of the PSI. However, future practitioners including only select dimensions of the PSI without the full 18-item Ferris et al. (2005) PSI, especially when using translated non-English versions of the subscales, should be concerned about the reliability of their assessments. The present study also found that the full 18-item PSI scale (Ferris et al., 2005) seems to have generally high internal consistency across student and employee samples, English and non-English samples, predominantly male and predominantly female samples, and when using both five- and seven-option response scales.
Limitations and Directions for Future Research
Although the average reliability estimates of the PSI measure and each dimension of the PSI were calculated and certain moderating variables that could explain the variability were studied, there were certain limitations regarding the lack of reliability and sample information that may have hindered the scope of this reliability generalization study. As previously mentioned, most of the samples included in this study did not provide estimates of reliability for each of the PSI dimensions (social astuteness, networking ability, interpersonal influence, and apparent sincerity) in addition to the overall PSI scale. The majority of the 101 samples included in the analysis only indicated the Cronbach’s alpha of the full PSI measure without reporting the reliability coefficients for the four PSI subdimensions, which limited the number of samples that were included in the analysis of the reliability of the four PSI dimensions. For example, there were only 27 samples in the articles we included that reported a reliability for networking ability, 27 that reported a reliability coefficient for interpersonal influence, 25 that reported a reliability coefficient for social astuteness, and 25 samples that reported a reliability coefficient for apparent sincerity.
In addition, although 101 samples were included in the final analysis of this reliability generalization of the PSI scale, many of the samples were missing information relating to gender and race that limited the use of gender and race as potential predictor variables in the analysis. Although gender was included as a predictor variable in the analysis by coding the percentage of males in the sample quartiles, previous reliability generalization studies have measured gender by coding all male or all female samples as 0 and all “mixed” samples with male and female participants as 1 (e.g., Vacha-Haase, 1998; Vacha-Haase et al., 2000). As none of the 101 samples in the current reliability generalization indicated they had exclusively all male or all female samples, samples were broken into four groups by their percentage of males (0%-25% male, 25%-50% male, 50%-75% male, and 75%-100% male) which did not allow for absolute distinctions to be made following the protocol of previous reliability generalization research regarding gender which have compared all male, all female, and mixed male and female samples (Vacha-Haase, 1998; Vacha-Haase et al., 2000).
In addition to the absence of all male and all female samples, racial and demographic information in the samples were not included in this reliability generalization of the PSI scale as potential moderator variables as racial and ethnic demographic information was provided in only 30 (28.85%) of the 101 possible samples that were included in our analysis. Future research on the PSI scale should seek to examine how the effects of gender and race influence the overall reliability of the PSI scale, especially as previous studies have found that subdimensions of political skill (e.g., networking ability) may have different inferences and interpreted differently depending on racial and ethnic group membership (Blass, Brouer, Perrewé, & Ferris, 2007). However, the results of the current study indicated that there were no significant overall differences in the weighted reliability of the full 18-item PSI scale based on language or geographic location, providing evidence that the measurement error of the PSI may likely not significantly differ based on ethnic group membership.
Although none of the potential sources of measurement error relating to sample differences individually significantly impacted the overall reliability of the PSI measure, the results of the current reliability generalization study of the PSI did seem to generally indicate that more homogeneous or demographically similar samples consisting of participants that were taken from relatively homogeneous populations generally tended to have a slightly lower degree of variability regarding the PSI’s interitem reliability compared with more heterogeneous samples that consist of individual participants taken from a more demographically diverse population. As a result, a general implication for future practitioners and researchers implementing the PSI is to employ data collection strategies that maximize the homogeneity of the sample population whenever possible such as sampling employee participants working at the same organization or with the same occupation type to mitigate any potential differences in measurement error in the sample that would generally be more likely to occur from utilizing data collection strategies that yield more heterogeneous samples. Future studies examining potential differences in the overall reliability estimates of the PSI measure between samples based on occupation type, organizational homogeneity, and other potential sources of systematic differences in measurement error between samples are needed to clarify this relationship.
Various moderators effecting the political skill job performance relationship have been identified by researchers, indicating that high levels of political skill are only associated with highest degree of performance without the presence of certain conditions (Zettler & Lang, 2015). For example, high levels of political skill are not associated with the highest levels of performance when individual conscientiousness is high, there are high levels of procedural and distributive justice in an organization, or organizational politics are high (Andrews, Kacmar, & Harris, 2009; Blickle, Weber, & Oerder, 2008). In addition, previous moderation analyses have found that the highest levels of political skill do not always yield the highest level of performance, thus the meta-theoretical principle of the TMGT effect “too much of a good thing is bad” may apply to the political skill construct (Andrews et al., 2009). Just as the TMGT effect applies to other nonmonotonic relations, it also explains why high political skill is associated with lower levels of performance than medium levels of political skill (Pierce & Aguinis 2013; Zettler & Lang, 2015). For example, extremely high levels of political skill may be associated with increased time networking rather than working, and expending effort for self-promoting purposes to achieve individual goals at the expense of the goals of the organization (Zettler & Lang, 2015). Given the PSI has a curvilinear relationship with job performance, it also seems possible that the reliability of the PSI may also fluctuate between those with different scores on the measure, indicating heteroskedasticity. Thus, it may be that the reliability of the PSI may be more or less reliable for those that report having high political skill compared with those that report having little political skill. Thus, future research could also seek to clarify if the reliability of the PSI is heteroskedastic and fluctuates across different scores on the measure.
Conclusion
In conclusion, the results of the present reliability generalization study provide novel insights to the organizational politicking literature by indicating that the (Ferris et al., 2005) full 18-item PSI scale has an acceptable weighted Cronbach’s alpha reliability coefficient across all of the samples that were identified in existing literature, a finding that adds to the body of research examining the measurement integrity of the PSI. The examination of the reliability of the PSI and its dimensions are vital to the construction of generalizable theories of political skill in future research. In practice and in research, the accurate implementation and administrative use of political skill assessments depend on the reliability of political skill measures. Thus, the results of the current meta-analysis offer valuable and novel insights of the psychometric characteristics of the PSI that can be utilized by future researchers and practitioners.
