Class Notes (1,100,000)

CA (620,000)

U of G (30,000)

PSYC (4,000)

PSYC 1010 (100)

David Stanley (3)

Lecture 1

# PSYC 1010 Lecture Notes - Lecture 1: Statistical Inference, Statistic, Descriptive Statistics

by OC112011

This

**preview**shows pages 1-3. to view the full**37 pages of the document.**Statistics

• The practice of collecting, analyzing, interpreting, and reporting

numerical data

Two Branches of Statistics

• Descriptive statistics

o Organizes, summarizes, and communicates a group of

numerical information

• Inferential statistics

o Using data collected from a representative group to draw

conclusions about a population

Descriptive Statistics

• Tend to take the form of tables, graphs, or single numbers that

consolidate a large amount of information

Inferential Statistics

• Techniques that use sample data to draw general conclusions about

the larger population

o Measuring everyone in the population is usually impossible

o Use sample statistics to infer what the population parameter

is likely to be

Populations and Samples

• Population: the set of observation of interest in a particular study

• Sample: A set of observations drawn from a population of interest

for inclusion in a study

• Parameter: A (usually numerical) value that describes a whole

population

• Statistic: A (usually numerical) value that describes a sample of the

population

Sampling Error

• Sampling error is the _____ between a sample statistic and a

population parameter

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

!

!

Basic Research Design

• Pick a population of interest (e.g., students)

o Decide how you will recruit a sample (who, how many, etc…)

• Pick a variable of interest (e.g., study habits)

o Decide how you will measure the variable

Turning Observations into Variables

o Observing people’s physical environment, attitudes, and

behaviour leads to variables – data that can take on different

values (vary)

Step 1: Define population and variables of interest

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

!

!

Step 2: Descriptive Statistics

Results

Sample A: Average study time =

Sample B: Average study time =

!

Step 3: Inferential Statistics

Sample data show

Two possibilities

•There is no real difference between the groups and sample

difference due to ________

•There is a difference between the groups and the sample data

reflects this

Use _______ to decide between the two alternatives

!

Turning observations into Variables

•Discrete variables

oVariables that can only take on only specific values (e.g.,

whole numbers)

oMeasures “how many”?

▪“how many letters are in your name?”

•Continuous variables

o Can take on a full range of values

o Measures “how much”?

▪“how tall are you?”

!

Always Discrete

###### You're Reading a Preview

Unlock to view full version