{'fraction_non_alphanumeric': 0.013986013986013986, 'fraction_numerical': 0.0, 'mean_word_length': 5.346774193548387, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Systematic Operant Bias Observed in Human Participants During Research on Choice

In experiments involving multiple operant behaviors, it is often assumed that the operants used are equivalent and neutral for the participants prior to the experiment. Otherwise the results can be affected by systematic operant bias that is not due to the intended independent variable. During a series of three studies designed to develop a new type of operant in order to study learning history variables, persistent systematic biases were observed; these could not be eradicated through methodological changes. The operants used required human participants to draw shapes on a computer graphics tablet; the biases that emerged were associated both with the hand motions involved in executing each operant and with the operant’s visual aspects. In some cases there was an interaction effect that combined the two sources of bias. Each experiment had a number of learning sessions in which participants practiced these operants different numbers of times, followed by a “test session” in which they were required to choose between them. The angle of lines drawn, the starting and ending point of each operant, the number of lines per operant, and the hand with which participants drew the lines were all varied, without elimination of operant bias; there remained persistent, classifiable preferences for certain operants over others. This type of detailed quantitative analysis of bias is potentially significant for any behavior research that assumes equivalence among operant behaviors.