Research Unit 10

Define a Type II error.

A Type II error occurs when a researcher concludes there is a significant effect (finding) when no significant effect actually exists. In other words - the null hypothesis is false and the researcher accepted it as true.

Define Type I error.

A type I error occurs when the researcher concludes a significant effect when no significant effect actually exists. See page 533. In other words - the null hypothesis is true and the researcher rejects it. See table on bottom of page 521

A null hypothesis is stated.The null hypothesis is, "There is no difference between one baby aspirin every day and no baby aspirin at all in prevention of myocardial infarction."

Accepting the null hypothesis when it actually is true means that the researcher concludes that there is no difference between 1 one baby aspirin and no baby aspirin in prevention of myocardial infarction, and there is no error.

A researcher who has conducted experimental research finds that in his 145-person hospital study the patients who are ambulated on the evening of abdominal surgery are less likely than the control group to develop postoperative pneumonia. What does the researcher infer?

Evening-of-surgery ambulation will prevent some cases of postoperative pneumonia in abdominal surgery patients.

A researcher reports that the heights of men aged 53 living in Rapid City, South Dakota, are between 5'7" and 6'0" and that the confidence interval is calculated at the p <.05 level. What does this mean?

If a 53-year-old man in Rapid City, South Dakota, is measured, there is a 95% chance that his height will fall in the 5'7" through 6'0" interval.

The data set is as follows: Ford, Ford, Chevy, Toyota, Ford, Ford, Chevy, Dodge, Dodge, Dodge, Ford, Subaru, Chevy, Toyota, Chevy. What measures of central tendency and dispersion will be used with this set?

Mode

One hundred students took an exam; the mean of the test was 45%, and the median was 38%; seventy students scored below the mean, but three scored more than 96%. This would represent what type of distribution?

Positively skewed

How may raw research data, with identifiers, obtained from a hospital be stored? (Select the two correct answers.)

b. In a password-protected computer, located in a private office or residence c. In a locked box in a safe

If a researcher wishes to predict with 97.5% accuracy, the level of significance would be

d. .025

According to our textbook, the lessons learned from a pilot study enable the researcher to do what?

refine the study protocol and data collection plan. See page 516