Abstract
While previous research into astrological predictions mainly focussed on natal astrology (Ridgley 1993; Tarvainen 2014; Klein 1993), horary astrology, which aims to predict the outcomes of daily events, has not been thoroughly tested.
A group of independent astrologers is conducting this research to confirm or refute the hypothesis that astrological forecasts of timing in horary astrology are random guesses. This is a pilot study in which a group of astrologers and a control group of random individuals made eleven predictions, each under completely identical initial conditions, with outcomes that could not be influenced. We are interested in only one metric—the deviation of the predicted time from the actual time of the event’s realization.
This pilot study’s task is to compare how much less astrologers err in indicating the timing of events compared to ordinary people.
The null hypothesis is that the errors of astrologers and random individuals differ insignificantly. The result showed that astrologers surpassed random individuals in accuracy by 3.5 standard deviations, i.e., Cohen’s d = 3.5, which is a large effect size. The difference in predictive accuracy between the two groups is highly significant (p < .00001) and is unlikely to be explained by chance.