PSY201: Intro

Question 1

Statistics

Answer 1

describe data - summarize, organize, interpret findings: relationship, effect of manipulation, how big that effect is
without stats, data + findings meaningless
provide ‘universal’ language (rules) to communicate results

Question 2

population

Answer 2

entire group of individuals

Rarely have opportunity to study entire category/group of interest

Question 3

parameters

Answer 3

Pop characteristics

Question 4

Sample

Answer 4

represent pop in research study

goal is to use results obtained from sample to help answer questions about pop

Question 5

statistics

Answer 5

Sample characteristics

Question 6

Variables

Answer 6

characteristic/condition that can change/take on different values

Question 7

Discrete variables

Answer 7

consist of indivisible categories (class size)

Question 8

continuous variables

Answer 8

infinitely divisible into whatever units researcher may choose (time/weight)

Question 9

Real Limits

Answer 9

boundaries located exactly half-way betw adjacent categories

Question 10

Independent Variable (IV)

Answer 10

manipulated; the manipulation is called a treatment

Question 11

DependentVariable

Answer 11

observed + measured to determine effect of treatment

Question 12

measuring variables

Answer 12

To establish relationships betw variables, researchers must observe variables + record observations

Question 13

scale of measurement

Answer 13

set of categories

Question 14

nominal scale

Answer 14

unordered set of categories identified only by name

measurements only permit you to determine whether 2 individuals same/different

Question 15

ordinal scale

Answer 15

ordered set of categories in terms of size

measurements tell you direction of diff betw two individuals.

Question 16

interval scale

Answer 16

ordered series of equal-sized categories

measurements identify direction + magnitude of difference zero point is located arbitrarily on an interval scale

Question 17

ratio scale

Answer 17

interval scale where value of zero indicates none of variable measurements identify direction + magnitude of difference + allow ratio comparisons of measurements

Question 18

Experiments

Answer 18

to demonstrate cause + effect relationship betw 2 variables show that changing value of 1 variable causes changes in a 2nd variable

Question 19

Experiments

Answer 19

one variable is manipulated to create treatment conditions. A second variable is observed and measured to obtain scores for a group of individuals in each of the treatment conditions.

Question 20

Experiments

Answer 20

measurements compared to see if there are diff betw treatment conditions
All other variables controlled to prevent them from influencing results

Question 21

Correlational Studies

Answer 21

to determine whether there is relationship betw 2 variables + to describe relationship
simply observes 2 variables as they exist naturally

Question 22

Non-experimental or quasi-experimental

Answer 22

don’t use manipulated variable to differentiate groups

variable that differentiates groups usually pre-existing participant variable (male/female)/time variable (before/after)

Question 23

Non-experimental or quasi-experimental

Answer 23

cannot demonstrate cause + effect relationships

similar to correlational research because they simply demonstrate + describe relationships

Question 24

Data

Answer 24

measurements obtained in research study

goal of statistics is to help researchers organize and interpret the data

Question 25

Descriptive statistics

Answer 25

Numbers used to simplify, summarize + describe data
Do not involve generalizing beyond description
descriptive value for pop = parameter
descriptive value for sample = statistic

Question 26

Descriptive statistics

Answer 26

avg scores used to summarize data

Tables/graphs used to organize data

Question 27

Inferential statistics

Answer 27

methods for using sample data to make general conclusions (inferences) about pops
sample data provide only limited info about pop
sample statistics generally imperfect representatives of corresponding pop parameters

Question 28

Sampling Error

Answer 28

discrepancy betw sample statistic + its pop parameter

Defining + measuring sampling error large part of inferential statistics

Question 29

Notation

Answer 29

X (X + Y if multiple scores): individual measurements/scores obtained for participant
# of scores in data set identified by N for pop/n for sample

Question 30

Notation

Answer 30

Summing set of values common in stats
Greek letter sigma, Σ: sum of
ΣX identifies the sum of the scores

Question 31

Order of Operations

Answer 31

1. All calculations within parentheses
2. Squaring/raising to other exponents
3. Multiplying + dividing
4. Addition (summation) with Σ notation
5. Subtraction