1Between-subjects with within-subjects designs
2Small N designs with large N designs.
In what circumstances would you use the within-subjects design and in what circumstances would you
use the large N design?
Hello,
Both between-subjects and within-subjects use participants to test conditions. Between-subjects design
is where different people test each condition, so everyone is only exposed to a single interface.
Whereas within-subjects are where the same individual tests all conditions and is exposed to all
interfaces. Large N designs look for patterns in many cases using random selection of cases (Myers &
Hansen, 2012). While small N design examine a small number of cases in depth using deliberate
selection of cases. In large N designs candidates are grouped, data from each group is studied instead of
individual data, and data is analyzed with statistics. In small N designs participants are in separate
experiments uses repeated measures, individual data is represented, and data is analyzed with visual
inspection. Small N designs are useful when there is not a large sample, there is interest in the
performance of an individual, and when a researcher wants to evaluate an intervention. Large N design
are useful when there are sufficient subjects, and a researcher wants to increase generalizability (Myers
& Hansen, 2012).
Myers, A., & Hansen, C. H. (2012). Experimental psychology (7th ed.). Belmont, CA:
Thomson/Wadsworth. ISBN-13: 9780495602316