Psych 300A Midterm 1 Review (Scales of Measurment))

Descriptive Stats

Describes what the data has to say

Inferential Stats

Lets us make use of samples and infer something about populations

Population

Set of all individuals intersted in a particular study

Parameter

value that describes a sample

Sample

subset of a population that is to be studied, should be representative of the population

Sampling error

Assumption that a sample is equivalent ot a popilation

T or F: Samples naturally oversitmate and underestimate characteristics

T, leads to sampling error

Measurement

Act of assigning a number/numeral to an attribute or property of an object, organism or event according to specific rules

What are the 4 scales of measurment

Nominal, Ordinal, Interval, Ratio

Nominal scale of measurement

Measures categories of something that are discriminable (one is not better/higher than another), deals with qualitative data

Ordinal scale of measurement

Measure and tells us the relative order of categories in comparison to one another but without equal distance between them

What is a common example of an ordinal scale of measurment

Likert scale

Likert Scale

When one is asked how satisfied they are on a scale of one to typically 7

T or F: Likert scales can sometimes be interval

T, only when the scale is standardized (e.g. with an intelligence likert scale)

Interval scale of measurement

Measures how much more of something there is, meaning that each value has equal distance between balies but has an arbitrary zero

What is a common example of an interval scale of measurment

temperature in degrees of fahrenheit celcius

Ratio scale of measurement

Measures proportion of values to each other, has equal intervals between numbers and a meaningful zero

How many decimal places should one compute with and how many should they round to in their final answer

Compute: 4-6 decimal places

Final Answer: 2 significant figures beyond the original value

How many decimal places should proportions be reported to

3-4 decimal places

Numeral

Graphic symbol used as a classification, code or label, had a qualitative interpretation

Number

numeral that has a quantitative interpretation

Datum

single observed value (X₀)

Data

Multiple observed values, can be continuous or discrete

Continuous number

Infinte number of possible values fall between any two observed values

Real limits

boundaries of intervals for scores that are represented on a continuous number line, have an upper and lower real limit (e.g. weight of 150 lb would have a limit of 149.5 - 150.5 lb)

Discrete number

Separate, indivisible categories with no possible values between units in a scale

Discrete continuum

When contious data is taken as discrete

What is an example of a discrete continuum

How one’s final grade in a class is grade but throughout the year it is given as a percentage

Independent variable

AKA predictor, the features of a study that are used to explain or explore the participants behaviour, can be manipulated or measured

Dependent variable

AKA criterion, the characteristic that is being predicted or the behaviour of participants that is being observed

What are the 4 different types of dependent variables?

1. Behavioural: participants behaviour

2. Attitudinal: participants feelings towards a topic

3. Cognitive: participants mental ability, thoughts and beliefs

4. Physiological: biological characteristics