Puzzle-solving in psychology: The neo-Galtonian vs. nomothetic research focuses

•We compare the neo-Galtonian and nomothetic research focuses.•A main difference is how approximation is restricted.•Neo-Galtonian approximation raises the issue of falsifiability.•General empirical facts can be falsified by the observation of single cases.•Falsified general facts can be repaired by contraction or expansion.

We compare the neo-Galtonian and nomothetic approaches of psychological research. While the former focuses on summarized statistics that depict average subjects, the latter focuses on general facts of form ‘if conditions then restricted outcomes’. The nomothetic approach does not require quantification as a convenient way of statistical modeling. The nice feature of a general fact is its falsifiability by the observation of a single case. Hence, as a clear sense of scientific error is re-introduced in the research paradigm, we detail two kinds of puzzle-solving: repairing general facts by contraction or by expansion of the initial conditions. This style of research does not require that researchers depend on highly skilled engineers in data analysis, as the very structure of a general fact can be established by scrutinizing a contingency table.