What is the commonly accepted probability level (p-value) used to declare significance in psychology research?

What is the commonly accepted probability level (p-value) used to declare significance in psychology research?

• A. 0.01
• B. 0.05
• C. 0.10
• D. 0.50

Answer: (B)

In psychology, the usual threshold for claiming a result is statistically significant is a p-value of 0.05. This means that if there were no real effect (the null hypothesis is true), you'd expect to see results as extreme as yours in about 5% of studies by chance alone. When the p-value falls below this cutoff, researchers reject the null, concluding the finding is unlikely to be due to random variation. This 0.05 level became a conventional standard because it strikes a familiar balance: it reduces the risk of false positives while not being so strict that genuine effects are routinely missed. Other options are not the standard: 0.01 would demand stronger evidence to declare significance, 0.10 would allow more false positives, and 0.50 is far too high to indicate anything meaningful.

In psychology, the usual threshold for claiming a result is statistically significant is a p-value of 0.05. This means that if there were no real effect (the null hypothesis is true), you'd expect to see results as extreme as yours in about 5% of studies by chance alone. When the p-value falls below this cutoff, researchers reject the null, concluding the finding is unlikely to be due to random variation.

This 0.05 level became a conventional standard because it strikes a familiar balance: it reduces the risk of false positives while not being so strict that genuine effects are routinely missed. Other options are not the standard: 0.01 would demand stronger evidence to declare significance, 0.10 would allow more false positives, and 0.50 is far too high to indicate anything meaningful.