Drinnon, Joy2023-01-132023-01-132022-11-30http://hdl.handle.net/11558/6851Hindsight bias is one of the biases that might influence decisions made in difficult situations, commonly known as the knew-it-all-along effect. The purpose of our study is to replicate both the studies of Walmsley et al. (2019) and Yama et al. (2021). A two-group study design was used with a convenience sample of 205 participants. Qualtrics, a web-based survey, was used to randomize participants into either a results group or a control group. We provide evidence of hindsight bias, including how it affects everyday people. We conducted an experiment with two dependent variables, each including three different hypotheses. We hypothesized that if a picture of a muddy riverbed and a photo of hailstorm clouds are shown to two groups of individuals while informing only one half of the group (Group A) of the flash flood and hailstorm actually occurring, then Group A will report that a flash flood and hailstorm will be more likely to occur whereas Group B will rate the likelihood of a flash flood and hailstorm to not be as probable. Two surprising themes emerged within the data collected. First, the results group responded with lower levels than expected in two of the six t-tests conducted – the ratings of the likelihood of a flash flood and the likelihood of a hailstorm. This resulted in a lack of statistical significance in both. Second, the results group rated the remaining four t-tests with statistically significant scores, showing that participants rated these probabilities as expected but did not rate the two main objectives as predicted. It demonstrated that even when posed with weather-related questions, people are frequently led by hindsight bias.en-USBiasBias, hindsightDecision-makingNatural disastersWorking Paper