5.3 Statistical Analysis: Chi Square

Question 1

What is a chi-square?

Answer 1

• a form of statistical analysis used to compare the actual results (observed) with the expected results

Question 2

What does a chi- square help to determine? (2)

Answer 2

• determine whether the data obtained experimentally provides a “good fit” to the expected data
• determine if any deviations from the expected results are due RANDOM CHANCE alone or to other circumstances (ex. Data collection error)

Question 3

Chi-square is designed to analyze ___ data.

Answer 3

Categorical

Question 4

The chi-squee equation is used to test the null hypothesis. What does it predict?

Answer 4

• predict that the data from the experiment will match the expected results

Question 5

The degrees of freedom is one less that the number of categories. What does the degree of freedom with the p value represent, if it is less than x^2?

Answer 5

X^2>critical value

• there is a statistical significant difference between the actual and expected values
• REJECT NULL HYP

Question 6

What happened if x^2 < critical value?

Answer 6

• there is not a statistical difference between the actual and expected values
• ACCEPT NULL HYPOTHESIS