Searching for Success: A Mixed Methods Approach to Identifying and Examining Positive Outliers in Development Outcomes

by Caryn Peiffer and Rosita Armytage, April 2018, Development Leadership Program Research Paper 52. Available as pdf

Summary: Increasingly, development scholars and practitioners are reaching for exceptional examples of positive change to better understand how developmental progress occurs. These are often referred to as ‘positive outliers’, but also ‘positive deviants’ and ‘pockets of effectiveness’.
Studies in this literature promise to identify and examine positive developmental change occurring in otherwise poorly governed states. However, to identify success stories, such research largely relies on cases’ reputations, and, by doing so, overlooks cases that have not yet garnered a reputation for their developmental progress.

This paper presents a novel three-stage methodology for identifying and examining positive outlier cases that does not rely solely on reputations. It therefore promises to uncover ‘hidden’ cases of developmental progress as
well as those that have been recognised.

The utility of the methodology is demonstrated through its use in uncovering two country case studies in which surprising rates of bribery reduction occurred, though the methodology has much broader applicability. The advantage of the methodology is validated by the fact that, in both of the cases identified, the reductions in bribery that occurred were largely previously unrecognised.

Introduction 1
Literature review: How positive outliers are selected 2
Stage 1: Statistically identifying potential positive outliers in bribery reduction 3
Stage 2: Triangulating statistical data 6
Stage 3: In-country case study fieldwork 7
Promise realised: Uncovering hidden ‘positive outliers’ 8
Conclusion 9
References 11
Appendix: Excluded samples from pooled GCB dataset 13

Rick Davies comment: This is a paper that has been waiting to be published, one that unites a qual and quant approach to identifying AND understanding positive deviance / positive outliers [I do prefer the latter term, promoted by the authors of this paper]

The authors use regression analysis to identify statistical outliers, which is appropriate where numerical data is available.. Where the data is binary/categorical is possible to use other methods to identify such outliers. See this page on the use of the EvaLC3 Excel app to find positive outliers in binary data sets.

Where there is no single Theory of Change: The uses of Decision Tree models

Eliciting tacit and multiple Theories of Change

Rick Davies, November 2012.Available as pdf  and a 4 page summary version

This paper begins by identifying situations where a theory-of-change led approach to evaluation can be difficult, if not impossible. It then introduces the idea of systematic rather than ad hoc data mining and the types of data mining approaches that exist. The rest of the paper then focuses on one data mining method known as Decision Trees, also known as Classification Trees.  The merits of Decision Tree models are spelled out and then the processes of constructing Decision Trees are explained. These include the use of computerised algorithms and ethnographic methods, using expert inquiry and more participatory processes. The relationships of Decision Tree analyses to related methods are then explored, specifically Qualitative Comparative Analysis (QCA) and Network Analysis. The final section of the paper identifies potential applications of Decision Tree analyses, covering the elicitation of tacit and multiple Theories of Change, the analysis of project generated data and the meta-analysis of data from multiple evaluations. Readers are encouraged to explore these usages.

Included in the list of merits of Decision Tree models is the possibility of differentiating what are necessary and/or sufficient causal conditions and the extent to which a cause is a contributory cause (a la Mayne)

Comments on this paper are being sought. Please post them below or email Rick Davies at

Separate but related:

See also: An example application of Decision Tree (predictive) models (10th April 2013)

Postscript 2013 03 20: Probably the best book on Decision Tree algorithms is:

Rokach, Lior, and Oded Z. Maimon. Data Mining with Decision Trees: Theory and Applications. World Scientific, 2008. A pdf copy is available