General Flashcards
Objectives of deceptive statistics?
To distinguish between different types of data measurement in psychology including qualitative, nominal (categorical) and numerical (continuous) measurement scales.
To explain some methods used to summarize and describe psychological data including category percentages and measures of mean, standard deviation and confidence intervals.
What is quantitative data?
Quantitative data encompass aspects of human thought and behaviour that are measured or reduced to numerical form.
Numbers data can be used in many different ways to measure psychological processes.
Analysis takes the form of descriptive and statistical calculations to interpret behaviour and explain relationships between the data acquired.
What is nominal measurement?
With nominal measurements, we classify people into discrete categories based on some individual characteristic or behavioural response.
Category descriptions are defined by words rather than numbers - have a response or not
Mutually exclusive - ppts should only be included under only one of the possible response categories.
Nominal measurements example?
Response category Male bystanders Female bystanders
Challenges thief 20 11
Ignores thief 8 15
Exits area 0 2
How to describe nominal data?
the only numerical operations available to us are to count the number of people or frequencies falling into each category
researchers often focus on the modal (most popular) response category within a particular condition (e.g. bystander type).
Converting the number of people falling into a particular response category to a percentage of the total number of people in that condition.
What is numerical measurement?
With numerical measurement, each person receives a separate numerical value or score on the characteristic or behaviour being measured.
The characteristic or response being considered is measured on a continuous numerical scale.
Types of numerical measurement?
Ordinal data
Interval data
Ratio data
What’s ordinal data?
This allows us to put people into rank order in terms of their position relative to each other (e.g. 1st, 2nd, 3rd) on the characteristic being measured but it does not tell us anything about the distances between different ranks.
Ordinal measurement is usually subjective.
What’s interval data?
On an interval scale, numbers are measured against a standard scale with designated units of measurement.
Consequently, not only can we put people into rank order on the scale, we can also say how large the differences are between people and compare one persons score on the same measurement scale used elsewhere.
What’s ratio data?
This is a special kind of interval data. Like interval data, ratio data is measured on a scale which has equal gaps or intervals between the points on the scale.
However, with interval data the zero-value on the scale, has no numerical significance attached to it. It does not signify a necessary end-point to the scale. It is merely a convenient but not an essential point on the scale.
The zero-point on a ratio scale signifies an absolute zero-value, a point on the scale below which it is not possible to measure. Interval or ratio scales are usually objective.
