This section describes how each author contributed to the study.  It indicates which authors contributed to experimental design, data collection, analysis, funding, writing, etc.

Professional example:

D. J. E. conceived and coordinated the study. K. K. performed the analysis in Figs. 1 and 5F. J. T. generated the data for Figs. 3A; 4, B and D; and 5, A–E. J. J. generated the data for Figs. 2 and 4, A and C. C. W. M. was responsible for Figs. 2D, 3B, 5G, 6, and 7. J. J., C. W. M., and D. J. E. were the primary contributors to the writing of the manuscript. All authors have reviewed the results and approved the final version of the manuscript. (MacDiarmid et al. 2016)

Student example:

AK, ZL, CM outlined the report together. AK ran the ANOVAs and chi-squared test and ZL ran the regression.  CM made figure 1, ZL made figure 2, CM made figure 3. ZL drafted the methods and results, AK drafted the introduction, and CM drafted the discussion, and AK and CM drafted the literature cited section. CM reviewed format and grammar. All authors contributed to revisions of all sections, reviewed the paper and approved the final version.