(Psyc 354) Exam 1 Study Guide

Study Guide: Exam 1

All exam questions are taken from Modules/Weeks 1 and 2, Nolan and Heinzen. There is no SPSS content. The study guide is organized by topic.

Populations and Samples:

Define what a sample is and identify the sample in a research scenario. For example, in a study with 15 student participants who have a mean SAT score of 678, what is the sample?

1.      What is the letter used to identify the sample size? In other words, the number of participants in a study is represented by what letter? n

Explain the difference between a sample and a population. Why are samples used more often than populations in research

Descriptive and Inferential Statistics:

Define a descriptive statistic and give an example. Be able to identify a descriptive statistic in a research scenario. For example, in a study with 15 student participants who have a mean SAT score of 678, what is the descriptive statistic?

1.      Define inferential statistics and explain how they are used by researchers. Inferntial statistics use sample data to make general estimates about the larger population. To infer or to make an intelligent guess about the population.

2.      Understand that the main difference between these two types of statistics (descriptive vs. inferential) is that one describes and summarizes the data set while the other uses the data to draw conclusions about a larger population.

Variables and Levels of Measurement:

1.      Define a variable. Variables are observations of physical, attitudinal, and behavioral characteristics that can take on different values.

2.      Define a value or score. Numbers that are given to a specific variable. What is the relationship between a variable and a value? Value is given to a variable. In this list, which is the variable and which is the value?  a.  IQ score(Variable)   b.  120(Value) 

3.      What is the difference between a discrete variable(can take on only specific values) and a continuous variable(can take on a full range of values)? Can you give an example of each one and identify why one is discrete while the other is continuous? DV: 1, 4, 7; how many times a week    CV: 1.2, 1.34, 2.684; how many seconds

4.      What are the 4 levels of measurement? Nominal, Ordinal, Interval, Ratio. Often, two of these levels are combined into one level. What is it called, and which 2 original levels are represented by it? Scale/Ratio and Interval

5.      List the 4 levels of measurement and describe whether they are discrete or continuous. Some can be both discrete and continuous.

·         Nominal- always discrete, never continuous

·         Ordinal- always discrete, never continuous

·         Interval- sometimes discrete, sometimes continuous

·         Ratio- seldom discrete, almost always continuous

Independent and Dependent Variables:

1.       An independent variable has at least two levels that we either manipulate or observe to determine its effects on the dependent variable.

2.       A dependent variable is the outcome variable that we hypothesize to be related to, or caused by, changes in the independent variable.

3.     We conduct research to see if the independent variable predicts the dependent variable.

4.      ? Ability to change the variable (male to female)

5.      A very basic example of an IV and its levels: