Analysis and Data Utilization

The Investment Model Scale (IMS-25) is a psychometric instrument developed on the basis of Rusbult’s Investment Model Theory, which explains why individuals initiate, maintain, or terminate close interpersonal relationships. According to the Investment Model, relationship commitment is determined by three primary factors: relationship satisfaction, quality of alternatives, and investment size. The IMS-25 evaluates these dimensions, providing a comprehensive assessment of the psychological mechanisms underlying commitment, relationship stability, and long-term relationship maintenance. The instrument has been extensively applied in social psychology, relationship research, family studies, counseling psychology, and clinical research to investigate romantic relationships, marital adjustment, interpersonal commitment, and relationship resilience. Beyond intimate relationships, the theoretical framework has also been adapted to organizational settings, friendships, educational environments, and other long-term interpersonal interactions where commitment plays a central role. This expanded description is based on the uploaded document.

Data analysis using the IMS-25 typically begins with descriptive statistical analyses, including means, standard deviations, medians, frequencies, percentages, percentile distributions, and score distributions for the total scale and each individual subscale. Scores are usually calculated separately for Relationship Satisfaction, Quality of Alternatives, Investment Size, and Commitment Level, allowing researchers to examine the relative contribution of each construct to relationship stability. Comparisons between demographic, relational, clinical, or cultural groups may subsequently be performed using independent-samples t-tests, paired-samples t-tests, one-way Analysis of Variance (ANOVA), repeated-measures ANOVA, Mann–Whitney U tests, or Kruskal–Wallis tests, depending on the characteristics and distribution of the collected data.

The psychometric evaluation of the IMS-25 includes assessment of internal consistency using Cronbach’s alpha and McDonald’s omega, test–retest reliability, and construct validity through Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA). Furthermore, convergent, discriminant, and criterion validity may be examined through correlations with validated measures of relationship satisfaction, dyadic adjustment, attachment style, trust, intimacy, communication quality, relationship quality, psychological well-being, emotional intelligence, and relationship stability.

Advanced statistical analyses may include Pearson or Spearman correlation analyses, multiple linear and logistic regression, mediation and moderation analyses, latent profile analysis (LPA), multilevel modeling, and Structural Equation Modeling (SEM) to investigate how satisfaction, investments, and perceived alternatives jointly influence commitment, relationship persistence, relationship dissolution, emotional adjustment, and long-term relational outcomes.

The IMS-25 is widely applied in relationship psychology, family psychology, counseling, psychotherapy, social psychology, healthcare research, educational research, and organizational behavior. It is particularly valuable for evaluating romantic relationships, marital functioning, couple interventions, relationship education programs, conflict resolution, and research examining interpersonal commitment across different populations and cultures.

The findings generated by the IMS-25 provide valuable information for psychologists, family therapists, counselors, researchers, healthcare professionals, and educators, supporting evidence-based interventions aimed at strengthening interpersonal commitment, improving relationship quality, enhancing communication, and promoting long-term relational well-being.

Objective

The primary objective of the Investment Model Scale (IMS-25) is to provide a reliable and valid assessment of the psychological factors that influence commitment and stability in close interpersonal relationships. The instrument enables researchers and clinicians to evaluate how relationship satisfaction, investment size, and perceived quality of alternatives contribute to individuals’ commitment, relationship maintenance, and long-term relational outcomes.

Furthermore, the IMS-25 supports research examining the relationships among commitment, attachment, relationship satisfaction, communication, conflict management, psychological well-being, relationship quality, and relationship longevity.

Scoring

The Investment Model Scale (IMS-25) consists of 25 items, typically rated on a 7-point Likert scale, ranging from 1 (Strongly Disagree) to 7 (Strongly Agree).

Responses are summed or averaged according to the scoring instructions to produce scores for the four principal dimensions:

• Relationship Satisfaction
• Quality of Alternatives
• Investment Size
• Commitment Level

Reverse-scored items should be recoded before calculating final scores.

• Higher scores on Satisfaction, Investment Size, and Commitment indicate greater relationship satisfaction, stronger psychological investment, higher commitment, and an increased likelihood of maintaining the relationship.
• Higher scores on Quality of Alternatives indicate that individuals perceive more attractive alternative relationships or life options, which may be associated with lower commitment and an increased probability of relationship dissolution.
• Lower scores on Satisfaction, Investment Size, and Commitment generally reflect weaker relational bonds, whereas lower Alternative scores indicate fewer attractive alternatives and greater dependence on the current relationship.

Interpretation of the results should consider participants’ age, relationship duration, marital status, cultural background, and complementary assessments of relationship quality, attachment style, communication patterns, conflict resolution, psychological well-being, and interpersonal functioning.

References (APA 7th Edition)

Agnew, C. R., Van Lange, P. A. M., Rusbult, C. E., & Langston, C. A. (1998). Cognitive interdependence: Commitment and the mental representation of close relationships. Journal of Personality and Social Psychology, 74(4), 939–954.

Le, B., Dove, N. L., Agnew, C. R., Korn, M. S., & Mutso, A. A. (2010). Predicting nonmarital romantic relationship dissolution: A meta‐analytic synthesis. Personal Relationships, 17(3), 377–390.

Rusbult, C. E. (1980). Commitment and satisfaction in romantic associations: A test of the Investment Model. Journal of Experimental Social Psychology, 16(2), 172–186.

Rusbult, C. E., Martz, J. M., & Agnew, C. R. (1998). The Investment Model Scale: Measuring commitment level, satisfaction level, quality of alternatives, and investment size. Personal Relationships, 5(4), 357–387.

Tran, S., & Simpson, J. A. (2009). Prorelationship maintenance behaviors: The joint roles of attachment and commitment. Journal of Personality and Social Psychology, 97(4), 685–698.