MAKING HYPOTHESES EXERCISE For each study described below, state the null hypothesis. Then review the results for the study and decide what your decision (accept or reject) should be with regard to the two hypotheses. Remember, you should NEVER accept a null hypothesis.

Study 1 Alternative Hypothesis: Anxiety increases lying in children.

Null Hypothesis:

Study 1 results: A study compared 50 children who were placed in an anxiety-inducing situation with 50 children in a control group. They were then asked about their behavior, and the number of inaccurate responses was recorded. Inaccurate responses did not differ for the two groups.

1. We should ___________ the null hypothesis. 2. We should ___________ the scientific hypothesis. 3. Suppose that the study described above was conducted inaccurately and that anxious children really do lie more. In this case, we have made a Type I Type II (circle one) decision error.

Study 2 Alternative Hypothesis: People are more likely to help a stranger if there is no one else around than if they are in a group (i.e., the bystander effect).

Null Hypothesis:

Study 2 results: A situation was set up on a busy highway where someone needed help with her car. Researchers observed 100 cars drive by and counted the number of people who stopped and whether they were alone or with other people in the car. People driving with others stopped less often to help than people who were driving alone.

1. We should ___________ the null hypothesis. 2. We should ___________ the scientific hypothesis. 3. Suppose that the above study contains a confounding variable, and when tested properly, people driving with others actually stop just as often as people driving alone. In this case, the study described above has led us to make a

Type I Type II (circle one) decision error.

Whenever we reject the null hypothesis, what does this tell us about the independent variable?