Don't make such black and white interpretations

Report effect sizes

Factors Determining the p-value

Test Statistic

Misinterpretations of the p-value

Alpha (Level of Significance)

p-hacking

The 2015 Ban on Null Hypothesis Testing

Alpha Criterion

What does a p value represent in the context of psychological research?

If a psychology researcher calculates a p-value of 0.08, they will typically declare the experimental result to be statistically significant.

A social psychologist is analyzing data from four different studies. Based on the standard thresholds for statistical significance provided in the table, match each study's obtained p value with its correct interpretation.

A psychologist is comparing findings across four different research studies. Based on the definition of a p value and the significance thresholds provided in the table, arrange these findings in order from the outcome LEAST likely to have occurred by chance to the outcome MOST likely to have occurred by chance.

According to the standard threshold of significance ($p = 0.05$) in psychology, a research result is typically declared significant if the probability of it occurring purely by chance is less than $1$ in how many?

Misinterpretation of the p Value

Determinants of the $p$ Value

Based on the significance thresholds provided in the table and the definition of a $p$ value, match each statistical label with the correct description of its probability occurring purely by chance.

A researcher obtains a $p$ value of $0.02$ and labels the result 'highly significant' ($**$). According to standard significance thresholds, where $* = p \leq 0.05$ and $** = p \leq 0.01$, this labeling is _____.

A cognitive psychologist conducts an experiment on learning styles and calculates a $p$ value of $0.04$. Applying the standard threshold of significance ($p = 0.05$) described in the text, the researcher should declare this result to be statistically significant.

According to the standard threshold of significance ($p = 0.05$), a psychological research result is typically declared significant if the probability of the outcome occurring purely by chance is less than 1 in _____.

Evaluate the following three experimental results and arrange them in order from the outcome representing the lowest probability of occurring purely by chance (1) to the outcome representing the highest probability of occurring purely by chance (3).

File Drawer Problem

p-hacking

Replication of Studies in Psychology

Example of Type I and Type II Errors

In null hypothesis testing, which of the following best defines a Type I error?

A researcher evaluates a new cognitive training program that, in reality, has no effect on memory. Due to an unusual sample, the statistical analysis produces a significant result, causing the researcher to incorrectly conclude that the program works. This situation describes a Type I error.

To understand a Type I error, one must distinguish between the true state of the population and the decision made by the researcher. Match each component of a Type I error to the description that best explains its role.

A Type I error is the result of a specific logical failure during the hypothesis-testing process. Arrange the following events in the correct order to illustrate the progression of a Type I error, starting from the actual state of the population to the researcher's final conclusion.

You are designing a computer simulation to help students visualize the logic of statistical decision-making in psychology. To successfully create a scenario where the software can generate a Type I error, which combination of population characteristics and decision rules must you program into the model?

In psychological research, a Type I error is also known as a 'false positive.'

A researcher must decide between two significance levels for a study on a new behavioral therapy. They evaluate the trade-offs and conclude that it is more damaging to give patients 'false hope' with a treatment that does not work than to miss a potentially helpful therapy. To align with this evaluation, the researcher selects a lower $\alpha$ level to minimize the probability of a _____.