Crowdsourcing hypothesis tests: Making transparent how design choices shape research results

To what extent are research results influenced by subjective decisions that scientists make as they design studies? Fifteen research teams independently designed studies to answer fiveoriginal research questions related to moral judgments, negotiations, and implicit cognition. Participants from two separate large samples (total N > 15,000) were then randomly assigned to complete one version of each study. Effect sizes varied dramatically across different sets of materials designed to test the same hypothesis: materials from different teams renderedstatistically significant effects in opposite directions for four out of five hypotheses, with the narrowest range in estimates being d = -0.37 to +0.26. Meta-analysis and a Bayesian perspective on the results revealed overall support for two hypotheses, and a lack of support for three hypotheses. Overall, practically none of the variability in effect sizes was attributable to the skill of the research team in designing materials, while considerable variability was attributable to the hypothesis being tested. In a forecasting survey, predictions of other scientists were significantly correlated with study results, both across and within hypotheses. Crowdsourced testing of research hypotheses helps reveal the true consistency of empirical support for a scientific claim.</div

Use of the words “brilliant” and “genius” on RateMyProfessors.com predicts the proportion of 2011 U.S. PhDs who are African American.

<p>Use of the words “brilliant” and “genius” on RateMyProfessors.com predicts the proportion of 2011 U.S. PhDs who are African American.</p

Frequency of “genius” and “brilliant” per millions of words of text on RateMyProfessors.com, split by gender and discipline.

<p>Frequency of “genius” and “brilliant” per millions of words of text on RateMyProfessors.com, split by gender and discipline.</p

Multiple regression analysis predicting African American representation at the PhD level.

<p>Multiple regression analysis predicting African American representation at the PhD level.</p

Use of the words “brilliant” and “genius” on RateMyProfessors.com predicts the percentage of 2011 U.S. PhDs who are female.

<p>Use of the words “brilliant” and “genius” on RateMyProfessors.com predicts the percentage of 2011 U.S. PhDs who are female.</p

Multiple regression analysis predicting Asian American representation at the PhD level.

<p>Multiple regression analysis predicting Asian American representation at the PhD level.</p

Multiple regression analysis predicting female representation at the PhD level.

<p>Multiple regression analysis predicting female representation at the PhD level.</p

Crowdsourcing hypothesis tests: making transparent how design choices shape research results

To what extent are research results influenced by subjective decisions that scientists make as they design studies? Fifteen research teams independently designed studies to answer five original research questions related to moral judgments, negotiations, and implicit cognition. Participants from two separate large samples (total N > 15,000) were then randomly assigned to complete one version of each study. Effect sizes varied dramatically across different sets of materials designed to test the same hypothesis: materials from different teams rendered statistically significant effects in opposite directions for four out of five hypotheses, with the narrowest range in estimates being d = -0.37 to +0.26. Meta-analysis and a Bayesian perspective on the results revealed overall support for two hypotheses, and a lack of support for three hypotheses. Overall, practically none of the variability in effect sizes was attributable to the skill of the research team in designing materials, while considerable variability was attributable to the hypothesis being tested. In a forecasting survey, predictions of other scientists were significantly correlated with study results, both across and within hypotheses. Crowdsourced testing of research hypotheses helps reveal the true consistency of empirical support for a scientific claim