Chapter 1- Intro to Statistics: Lecture Material

Question 1

variables

Answer 1

characteristic that can change or take on different values, must be able to vary

• most research begins with a general question about the relationship between two variables for a specific group

Question 2

Population

Answer 2

An entire group of individuals

Question 3

Sample

Answer 3

• Samples are selected to represent the population, because normally populations are too large to examine the entire group
• The goal is to use results from the sample to answer questions about the population

Question 4

inferential statistics

Answer 4

use sample data to draw general conclusions (inferences) about populations

defining and measuring sampling error is a large part of inferential statistics

Question 5

descriptive statistics

Answer 5

• methods for organizing and summarizing data
• Tables or graphs used to organize data
• Descriptive values used to summarize data

Question 6

parameter

Answer 6

• descriptive value for a population

Question 7

statistic

Answer 7

descriptive value for a sample

sample statistics are not perfect representatives of pop parameters

Question 8

Sampling error

Answer 8

the discrepancy between a sample statistic and its population parameter

Question 9

data

Answer 9

• goal of statistics is to help researches organize and interpret data
• measurements obtained in research are called data

Question 10

discrete variables

Answer 10

• consist of indivisible categories

ex. dice roll, football game points

Question 11

continuous variables

Answer 11

are infinitely divisible into any unit the researcher chooses

Question 12

nominal scale

Answer 12

• unordered set of categories identified by name only
• only determination you can make is whether two individuals are the same or different on that variable

Question 13

ordinal scale

Answer 13

• ordered set of categories
• can tell the direction of difference between two individuals

ex. class rank, placing in a race

Question 14

interval scale

Answer 14

• an ordered series of equal sized categories
• can identify the direction and magnitude of differences
• zero point is arbitrary

ex. temperature in degrees F or degrees C

Question 15

ratio scale

Answer 15

• interval scale where a value of zero indicates none of the thing
• identifies direction and magnitude of difference

ex. temperature in Kelvin

Question 16

correlation

Answer 16

• goal is to determine strength and direction of the relationship between two variables
• uses observation of two variables as they exist naturally
• correlation does not equal causation

Question 17

experiments

Answer 17

• examine the relationship between 2 or more variables by changing one variable and observing the effects on the other variable

can only switch one variable at a time, ideally all other variables are controlled to prevent them from influencing the results

Question 18

nonexperimental studies

Answer 18

• nonexperimental studies are similar to experiments because they also compare groups of scores
• they do not use a manipulated variable to differentiate between groups
• the independent variable is a pre-existing participant variable (male/female, before/after)
• no manipulations= no casual determinations (you cannot control for competing explanations of findings)

ex. relationship quality in couples making the transition into parenthoo

Question 19

PEMDAS

Answer 19

summation w sigma notation comes before other addition and subtraction