Essential theory Flashcards
Choice of statistic, or statistical test, depends
on 4 things
What are they?
- Scale of measurement
- Research aims
- Experimental design
- Properties of dependent/outcome variable
What are the 3 types of research aims?
- Descriptive only
- Relational (correlation)
- Experimental (differences)
What type of test do we use for normally distributed data?
Parametric
What type of test do we use for not normally distributed data?
Non-parametric
What 3 things do we look for in an experiment based on its experimental design?
- Subjects design (between or within)
- Number of independent variables (IVs)
- Number of IV levels
What are the 4 types of scales of measurement?
- Nominal
- Ordinal
- Interval
- Ratio
- Nominal
- Ordinal
- Interval
- Ratio
These are…?
Scales of measurement
Which scales of measurement are used for categorical data?
Nominal
Which scales of measurement are used for discrete or continuous data?
- Ordinal
- Interval
- Ratio
What is nominal data?
Numbers or names serve as labels but no numerical relationship between values
e.g. gender, political party, religion
Numbers or names serve as labels but no numerical relationship between values
e.g. gender, political party, religion
This is known as…?
Nominal data
What is ordinal data?
Data is organised by rank
Values represent true numerical relationships but intervals between values may not be equal
e.g. race position, likert scale ratings
What is interval data?
True numerical relationships and intervals between values are equal but scale has not true zero point
e.g. temperature (ºF), shoe size
What is ratio data?
True numerical relationships, equal intervals and true zero point
e.g. height, distance
Data is organised by rank
Values represent true numerical relationships but intervals between values may not be equal
e.g. race position, likert scale ratings
This is known as…?
Ordinal data
True numerical relationships and intervals between values are equal but scale has not true zero point
e.g. temperature (ºF), shoe size
This is known as…?
Interval
True numerical relationships, equal intervals and true zero point
e.g. height, distance
This is known as…?
Ratio
A study’s research aim is to describe
What descriptive statistics should be used?
Summarise a set of sample
values
What research aim does not allow us to make predictions and infer causality?
The research aim to describe
What are the 2 statistics used in a study following the research aim of describing?
- Central tendency
- Spread
What are the 3 types of measure of central tendency?
- Mean
- Median
- Mode
What are the 2 types of measure of spread?
- Standard deviation
- Range
When do we use the mean as a measure of central tendency?
When data is:
- Discrete or continuous
- Normally distributed
When data is:
- Discrete or continuous
- Normally distributed
We use…?
a. Mode
b. Mean
c. Median
b. Mean
When do we use the median as a measure of central tendency?
When data is:
- Discrete or continuous
- Not normally distributed
When data is:
- Discrete or continuous
- Not normally distributed
We use…?
a. Mode
b. Mean
c. Median
c. Median
When do we use the mode as a measure of central tendency?
When data is categorical
When do we use standard deviation as a measure of spread?
When data is:
- Discrete or continuous
- Normally distributed
When data is:
- Discrete or continuous
- Normally distributed
We use…?
a. Standard deviation
b. Range
a. Standard deviation
When do we use range as a measure of spread?
When data is:
- Discrete or continuous
- Not normally distributed
When data is:
- Discrete or continuous
- Not normally distributed
We use…?
a. Standard deviation
b. Range
b. Range
Relational research explore …?
The relationship between observed behaviours or phenomena
True or False?
Relational research actively manipulate variables
False
Nothing is actively manipulated in relational research
What type of research aim allows us to make predictions but not infer causality?
Relational research
Explores relationship between observed behaviours or phenomena
a. Describe
b. Infer differences
c. Infer relationships
c. Infer relationships
Summarise a set of sample
values
a. Describe
b. Infer differences
c. Infer relationships
a. Describe
Examines the influence of one or more variables (IVs) on other variables (DVs)
a. Describe
b. Infer differences
c. Infer relationships
b. Infer differences
Experimental research examines …?
The influence of one or more variables (IVs) on other variables (DVs)
We cannot make predictions or claims of causality
a. Describe
b. Infer differences
c. Infer relationships
a. Describe
We can make predictions but not claims of causality
a. Describe
b. Infer differences
c. Infer relationships
c. Infer relationships
We can make predictions and claims of causality if confounding variables are controlled for
a. Describe
b. Infer differences
c. Infer relationships
b. Infer differences
True or False?
We can always make claims about causality regardless of whether we have controlled for confounding variables
False
We can only make claims about causality IF we have controlled for confounding variables
How does experimental research control for confounding variables?
List 2 ways
- Random allocation (between-subjects)
- Counterbalancing (within-subjects)
When is controlling for confounding variables not possible?
Quasi-experimental design
What type of research manipulates a small number of variables to measure the effect of the manipulated variables?
a. Descriptive
b. Relational
c. Experimental
c. Experimental
What is an IV?
Hypothesised to influence the DV
The IV is measured on a ____ scale
a. Categorical
b. Discrete
c. Continuous
a. Categorical
What is a DV?
Hypothesised to be ‘dependent’ on the IV
The DV is measured on a ____ scale
a. Categorical
b. Discrete
c. Continuous
b. Discrete
c. Continuous
Why do we measure the DV under different levels of the IV?
To determine the effect of the IV
How do we determine the effect of the IV?
We measure the DV under different levels of the IV
List 2 characteristics of true-experimental IVs
- IVs are actively manipulated
- Random allocation is possible (can make claims about causality)