Interpersonal Power Inventory (IPI)

Abstract

The Interpersonal Power Inventory (IPI) is a psychological scale designed to measure the perceived use of various power bases or influence strategies employed by an agent (such as a counselor or supervisor) toward a target (a client or subordinate). Developed by Raven, Schwarzwald, and Koslowsky in 1998, the IPI operationalizes and expands upon the classic French and Raven (1959) taxonomy of social power, providing a refined, multidimensional assessment instrument suitable for diverse relational contexts, including organizational and therapeutic settings. The scale is structured to capture how different types of perceived influence affect the target’s likelihood of compliance.

Keywords

Interpersonal Power Inventory, IPI, Bases of Power, Social influence, organizational psychology, counseling, compliance, supervisor-subordinate relationship, psychological scale, Raven’s taxonomy.

Authors

Bertram H. Raven, Joseph Schwarzwald, Moshe Koslowsky.

Purpose

The primary purpose of the Interpersonal Power Inventory is to systematically quantify the specific types of power or influence strategies utilized by an influencing agent and perceived by the target individual within a relationship hierarchy. The scale aims to distinguish among 11 refined bases of power, moving beyond the original five categories proposed by French and Raven, to provide a nuanced understanding of interaction dynamics and the resulting behavioral compliance or resistance. It serves as a diagnostic tool to assess influence effectiveness in professional and managerial roles.

The IPI is particularly valuable in research exploring organizational behavior, leadership styles, and therapeutic outcomes, where understanding the mechanics of social influence is critical. By providing parallel versions (Superiors/Counselor and Employee/Client), the instrument allows for the study of power dynamics across different professional environments.

Construct

The IPI measures the construct of Interpersonal Power, defined as the potential ability of one person (the agent) to influence the behavior, attitudes, or cognitions of another person (the target). This construct is fundamentally rooted in the Power/Interaction Model of Interpersonal Influence. The scale operationalizes 11 distinct bases of power, which are categorized as follows:

• Reward Power: Split into impersonal (e.g., formal benefits) and personal (e.g., approval, liking) rewards.
• Coercive Power: Split into impersonal (e.g., difficult assignments, penalties) and personal (e.g., disapproval, coldness) coercion.
• Legitimate Power: Split into Legitimate Position (formal authority), Legitimate Reciprocity (owing a debt), Legitimate Equality (working towards a shared goal), and Legitimate Dependence (agent relies on target).
• Referent Power: Based on identification, respect, and admiration.
• Expert Power: Based on specialized knowledge or competence.
• Information Power: Based on the logical clarity and persuasive quality of the explanation provided for the request.

Validity

The validation of the IPI focused heavily on establishing its conceptual clarity and structural integrity, ensuring that the 11 proposed factors were distinct and measurable. The scale demonstrates strong construct validity, as its structure directly reflects the theoretical expansion of the Bases of Power model into more refined subcategories, which is necessary to capture subtle differences in influence strategies used in real-world settings.

Furthermore, criterion-related validity has been supported in studies showing that scores on specific power bases correlate meaningfully with relevant outcomes, such as job satisfaction, organizational commitment, and therapeutic alliance effectiveness, depending on the version used. The development process involved rigorous item generation and selection to ensure high face validity and content coverage across the breadth of influence strategies.

Reliability

While specific statistical reliability coefficients (e.g., Cronbach’s Alpha) are detailed in the original 1998 publication, the IPI is generally reported to possess high internal consistency across its various subscales. The refinement of the power bases into 11 distinct dimensions ensures that items within each factor are highly correlated, providing reliable measurement of that specific influence technique.

Factor Analysis

The IPI was developed using extensive factor analysis techniques, specifically confirmatory factor analysis (CFA), to test the hypothesized structure of the 11 bases of power. This analysis confirmed that the expanded conceptualization—which separates, for instance, impersonal reward from personal reward—provides a better fit to empirical data than the traditional five-factor model.

The successful delineation of these factors is crucial for the scale’s utility, confirming that influence tactics perceived by targets are not monolithic. For example, the IPI distinguishes between Expert power (knowledge) and Information power (clarity of explanation), showing them to be empirically separate factors contributing uniquely to the overall influence process.

Instrument

Test Type: Self-report psychological scale

Format: Multi-item questionnaire with two distinct versions (Superiors/Counselor and Employee/Subordinate).

Language Available: English (Original).

Population Group: Professionals in hierarchical relationships (e.g., supervisors, managers, counselors) and their respective targets (employees, clients).

Age Group: Adult (Generally employed or receiving professional services).

Population Details: The scale is adaptable for use in various organizational and clinical settings where power differentials exist. It is commonly used in studies of leadership, management, and counseling psychology.

Test Methodology: Respondents rate their likelihood of compliance or agreement with the agent’s request based on the stated reason (the power base). The response scale is a 7-point scale, ranging from “Much less likely to comply” to “Much more likely to comply.”

Keywords

Interpersonal influence, Bases of Power, organizational behavior, compliance, social psychology, leadership assessment, therapeutic alliance, Likert scale, IPI, social influence.

Authors

Author ORCID Identifier: Not provided in source materials.

Affiliation Email addresses: Not provided in source materials.

Correspondence Address: Not provided in source materials.

Permissions & Fee and Test Year

The scale was first published in 1998 in the Journal of Applied Social Psychology. Researchers should consult the primary author, Bertram H. Raven, or the publisher for current permissions regarding non-commercial or commercial use. The original instrument can be found referenced in academic databases and publications. The original PDF can be downloaded here: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.934.6508&rep=rep1&type=pdf.

Reference’s

• Raven, B.H., Schwarzwald, J., & Koslowsky, M. (1998). Conceptualizing and measuring a power/interaction model of interpersonal influence. Journal of Applied Social Psychology, 28(4): 307–332.
• Raven, Bertram H. (1992). A Power/Interaction Model of Interpersonal Influence: French and Raven Thirty Years Later. Journal of Social Behavior and Personality, 7:217-244.
• Anderson, Ruthann Smith. (2008). Counselor Gender Self-Confidence and Social Influence In Counseling: Counselor Perceptions of the Therapeutic Alliance. Ohio University. Ph.D. dissertation.

Items of the Interpersonal Power Inventory (IPI)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

Interpersonal Power Inventory- Superiors Version

1. A good evaluation from me could lead to an earlier release from court-ordered counseling or other benefits.
2. After all, I am the counselor, and the client should feel some obligation to go along.
3. He/she probably feels I know the best way to handle the situation.
4. Once I point it out, he/she can see why the change is necessary.
5. He/she admires or respects me and does not wish to disagree.
6. I can give the client more difficult assignments.
7. I have done some nice things for him/her in the past and so he/she does this in return.
8. He/she likes me and my approval is important to him/her.
9. It is clear that I really depend on the client to do this for me.
10. He/she does not want me to dislike him/her.
11. By doing so, he/she can make up for some difficulties he/she may have caused in the past.
12. For past considerations he/she has received, he/she feels obliged to comply.
13. I can make things unpleasant for clients.
14. It makes the client feel better to know I like him/her.
15. He/she sees me as someone he/she can identify with.
16. He/she knows that unless he/she does so, my job will be more difficult.
17. I have carefully explained the basis for this request.
18. It would be disturbing for the client to know that I disapprove of him/her.
19. He/she feels I probably know more about this particular situation.
20. It is my job to tell him/her how to handle this situation.
21. Complying helps make up for things he/she has not done so well previously.
22. I can help the client receive special benefits.
23. I may be cold and distant if he/she does not do as requested.
24. I gave the client good reasons for changing how he/she handled the situation.
25. He/she understood that I really needed his/her cooperation on this.
26. He/she trusts me to give him/her the best direction.
27. We are both working towards the same goal and should see eye to eye on things.
28. I have the right to request that he/she handle the situation in a particular way.
29. I make the client feel more valued when he/she does as requested.
30. He/she has made some mistakes and therefore feels that he/she owes this to me.
31. I can make it more difficult for him/her to get an earlier release from court ordered counseling or obtain other benefits.
32. I can help him/her get reduced counseling fees.
33. I have previously done some good things that he/she has requested.
34. It makes the client feel personally accepted when he/she does as asked.
35. As a client, he/she has an obligation to do as I say.
36. He/she looks up to me and generally models his/her behavior accordingly.
37. He/she has not always done what I have asked so this time feels he/she should.
38. He/she feels that I probably have more knowledge about this than he/she does.
39. I can make it more difficult for him/her to get reduced counseling fees.
40. He/she realizes that a counselor needs assistance and cooperation from clients.
41. He/she expects some favorable consideration from me for going along on this.
42. He/she now understands why the recommended change is for the better.
43. I have let the client have his/her way earlier so he/she feels obliged to comply now.
44. He/she would be upset knowing that he/she was on the bad side of me.

Employee Version

1. A good evaluation from my supervisor could lead to an increase in pay.
2. After all, he/she was my supervisor.
3. My supervisor probably knew the best way to do the job.
4. Once it was pointed out, I could see why the change was necessary.
5. I respected my supervisor and thought highly of him/her and did not wish to disagree.
6. My supervisor could give me undesirable job assignments.
7. My supervisor had done some nice things for me in the past so I did this in return.
8. I liked my supervisor and his/her approval was important to me.
9. It was clear to me that my supervisor really depended on me to do this for him/her.
10. I didn’t want my supervisor to dislike me.*
11. By doing so, I could make up for some problems I may have caused in the past.
12. For past considerations I had received, I felt obliged to comply.
13. My supervisor could make things unpleasant for me.
14. It made me feel better to know that my supervisor liked me.
15. I saw my supervisor as someone I could identify with.
16. Unless I did so, his/her job would be more difficult.
17. My supervisor had carefully explained the basis for the request.
18. It would have been disturbing to know that my supervisor disapproved of me.
19. My supervisor probably knew more about the job than I did.
20. It was his/her job to tell me how to do my work.
21. Complying helped make up for things I had not done so well previously.
22. My supervisor could help me receive special benefits.
23. My supervisor may have been cold and distant if I did not do as requested.
24. My supervisor gave me good reasons for changing how I did the job.
25. I understood that my supervisor really needed my help on this.
26. I trusted my supervisor to give me the best direction on this.*
27. We were both part of the same work group and should have seen eye-to-eye on things.
28. My supervisor had the right to request that I do my work in a particular way.
29. My supervisor made me feel more valued when I did as requested.
30. I had made some mistakes and therefore felt that I owed this to him/her.
31. My supervisor could make it more difficult for me to get a promotion.
32. My supervisor had previously done some good things that I had requested.
33. It made me feel personally accepted when I did as my supervisor asked.
34. As a subordinate, I had an obligation to do as my supervisor said.
35. I looked up to my supervisor and generally modeled my work accordingly.
36. I had not always done what he/she wished, so this time I felt I should.
37. My supervisor’s actions could help me get a promotion.
38. My supervisor probably had more technical knowledge about this than I did.
39. My supervisor could make it more difficult for me to get a pay increase.
40. I realized that a supervisor needs assistance and cooperation from those working with him/her.
41. I expected to get some favorable consideration for this.
42. I could then understand why the recommended change was for the better.
43. My supervisor had let me have my way earlier so I felt obliged to comply now.
44. Just knowing that I was on the bad side of my supervisor would have upset me.

Response Scale (Likelihood of Compliance)

1. Much less likely to comply.
2. A bit less likely to comply.
3. A bit more likely to comply.
4. Would not affect their tendency to comply.
5. Less likely to comply.
6. More likely to comply.
7. Much more likely to comply.