In diary studies, people provide frequent reports on the events and experiences of their daily lives. These reports capture the particulars of experience in a way that is not possible using traditional designs. We review the types of research questions that diary methods are best equipped to answer, the main designs that can be used, current technology for obtaining diary reports, and appropriate data analysis strategies. Major recent developments include the use of electronic forms of data collection and multilevel models in data analysis. We identify several areas of research opportunities: 1. in technology, combining electronic diary reports with collateral measures such as ambulatory heart rate; 2. in measurement, switching from measures based on between-person differences to those based on within-person changes; and 3. in research questions, using diaries to (a) explain why people differ in variability rather than mean level, (b) study change processes during major events and transitions, and (c) study interpersonal processes using dyadic and group diary methods.

The recent growth in diary and experience sampling research has increased research attention on how people change over time in natural settings. Often however, the measures in these studies were originally developed for studying between-person differences, and their sensitivity to withinperson changes is usually unknown. Using a Generalizability Theory framework, the authors illustrate a procedure for developing reliable measures of change using a version of the Profile of Mood States (POMS; McNair, Lorr, & Droppleman, 1992) shortened for diary studies. Analyzing two data sets, one composed of 35 daily reports from 68 persons experiencing a stressful examination and another composed of daily reports from 164 persons over a typical 28-day period, we demonstrate that three-item measures of anxious mood, depressed mood, anger, fatigue, and vigor have appropriate reliability to detect within-person change processes.Keywords diary studies; daily mood; within; person change; reliability; Generalizability Theory Correspondence concerning this article should be addressed to James A. Cranford, Addiction Research Center and Department of Psychiatry, University of Michigan, 2025 Traverwood Drive, Suite A, Ann Arbor, MI 48105-2194; e-mail: jcranfor@med.umich.edu; Patrick E. Shrout, 6 Washington Place, Mail Room 416b, Department of Psychology, New York University, New York, NY, 10003; e-mail: pat.shrout@nyu.edu; or Niall Bolger, 406 Schermerhorn Hall, 1190 Amsterdam Avenue, Department of Psychology, Columbia University, New York, NY, 10027; e-mail: nb2229@columbia.edu. James A. Cranford, Addiction Research Center, Department of Psychiatry, University of Michigan; Patrick E. Shrout and Masumi Iida, Department of Psychology, New York University; Eshkol Rafaeli, Psychology Department, Barnard College, Columbia University; Tiffany Yip, Department of Psychology, Fordham University; Niall Bolger, Department of Psychology, Columbia University. 2 In principle, it is possible to estimate the between-person reliability coefficient for mood by averaging a randomly selected set of days (R KR ). Because this is not a design that has obvious advantages, the generalizability coefficient is not presented here, but it is R KR available from the authors on request. NIH Public Access Author ManuscriptPers Soc Psychol Bull. Author manuscript; available in PMC 2008 June 6. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptDaily diary designs are increasingly recommended for studying dynamic psychological processes such as emotional states, self-regulation, and appraisals of social situations (Bolger, Davis, & Rafaeli, 2003;. They have the potential to provide high-resolution information about evolving psychological processes, and they minimize retrospection artifacts and biases. Yet, they are not without their own methodological difficulties . Diary studies impose substantial demands on participants, and the burden imposed by protocols that require frequent self-reports may lead to biases in samples of participa...

Concern has been raised about the lack of participant compliance in diary studies that use paper-and-pencil as opposed to electronic formats. Three studies explored the magnitude of compliance problems and their effects on data quality. Study 1 used random signals to elicit diary reports and found close matches to self-reported completion times, matches that could not plausibly have been fabricated. Studies 2 and 3 examined the psychometric and statistical equivalence of data obtained with paper versus electronic formats. With minor exceptions, both methods yielded data that were equivalent psychometrically and in patterns of findings. These results serve to at least partially mollify concern about the validity of paper diary methods.

The literature on social support within dyadic intimate relationships raises a seeming paradox: The availability of support tends to reduce distress, but its actual receipt is often unhelpful and at times engenders feelings of inadequacy, indebtedness, and inequity—unintended but potent side effects of the support transaction. Our review organizes this literature in order to solve the apparent paradox. Specifically, we theorize that, because support attempts are often unskilled and miscarried, they lead to greater costs than benefits. We identify four ways in which dyadic support can be unskillful, ways pertaining to its timing, content, process, or reciprocation. We suggest that when these are addressed, support can regain its intended goals of enhancing dyadic coping, reducing stress, and strengthening relationships.