5 Written questions
5 Matching questions
 placebo control groups
 ecological generalizability
 analysis of covariance
 mortality:
 trend study
 a the degree to which results of a study can be applied to to other settings or conditions
 b used to survey different samples from a population whose members may change over time
 c participants are given a treatment unrelated to the real treatment
 d this tests the main and interaction effects of categorical variables on a continuous dependent variable, controlling for the effects of selected other continuous variables that covary with the dependent variable
 e participant matching and omission
5 Multiple choice questions
 a statistical procedure for examining the results of several research studies on the same topic and determining the congruence and divergence of outcome data
 participants receive no treatment at all
 random selection, random assignment
 random selection, random assignment
 1. Standardize the conditions in which the study occurs.
2. Know the characteristics of the participants in the study
3. Know the details of the study, such as where, when, and the extraneous events that may occur
4. Plan and chose a suitable design
5 True/False questions

Methods of Control: → randomization
random assignment
matching
using participants as their own controls
analysis of covariance 
contentrelated evidence → asks the question of whether the instruments and the sample accurately represent the variable under study. A researcher would ask whether the questions used in the instrument adequately assess the variable under study. To ensure contentrelated validity, researchers should look over the content and format of the instrument to be used

survey research → describes the characteristics of a population by selecting a representative sample of respondents to research

statistical regression → omitting extreme scores, randomization

random assignment → a randomization process that is usually done after the research participants are selected to determine which participants will receive which value of the independent variable