KEY WORDS Flashcards
What is the null hypothesis
States that any difference or relationship expected is due to chance- there is no relationship or difference as predicted. It is this type of hypothesis that is tested when using statistical tests
What is an experimental hypothesis
This is the statement of what is expected. It is also called the alternative hypothesis (alternative to the null hypothesis)
What is a directional (one tailed) hypothesis
The direction that the results will take is predicted
What is a non directional (two tailed) hypothesis
There is no direction predicted for the results
Dependent variable
Measured by researcher. Changes as a results of manipulating the IV
Independent variable
Changed or manipulated by researcher. This is to see the effect on the DV
What are other variables that might affect the results of a study called
Extraneous variables
What are extraneous variables
Other variables which can affect the results of a study as well as, or instead of, the IV. examples are…..
Participants variables…age, gender, mood
Situational variables….temp,noise,interruptions, light
When extraneous variables are not controlled for and affect results they are called confounding variables
What is a hypothesis
Statement of what is expected
What are measures of central tendency? Examples?
is a single number which give you information regarding where the rest of the scores lie.
Examples…. Mean, mode, median
What are measures of dispersion? Examples?
Measures of dispersion are descriptive statistics that describe how similar a set of scores are to each other
The more similar the scores are to each other, the lower the measure of dispersion
Examples….range, variance
What is a critical value
the value that would have been obtained if chance alone contributed to the outcome at the chosen level of significance ( it is shown in the null hypothesis)
What is an observed value
the value you obtain from the test statistic to be compared with the critical value
Define credibility
the quality of being believed or trusted
What is a level of significance
The probability that the results are due to chance
How is a level of significance chosen
Depends on what is being tested. If the tested has been carried out previously and found to be true, it might be reasonable to ask for 1 in 100 of the results or fewer to be due to chance. If the study is new, and not known what is likely then the result of 1 in 20 being due to chance might be a good result. Also depends on how serious the consequences of the study might be
What is a control group
It is composed of participants who do not receive the experimental treatment. They allow for comparisons against the experimental group to see the reflect of whatever they are studying
Define levels of measurement
refers to the way that a variable is measured
3 examples of levels of measurement
Nominal, ordinal and interval/ratio data
What is nominal data
Data in categories, mode is suitable
What is ordinal data
Data in ranks such as rating scales, mode and median are suitable
What is interval/ratio data
Mathematical scores, all three measures of central tendency are suitable
What is concordance
Means agreement
Eg. If one twin has a characteristic and the other twins does aswell, there is concordance
If one twin has a characteristic and the other twin does not, there is no concordance
What is a continuum
A graded scale from one point to another
What is a survey
An interview or a questionnaire. It is a planned research method with a specific aim in mind and a specific hypothesis
What is a questionnaire
A set of written questions which are usually highly structured. They can come in many different forms including face to face interviewing and hand out, postal or telephone questionnaires. Different formats can be used including likert scales, rating scales, identifying characteristics, open questions
What is an interview
It involves a face to face situation and a series of questions. They can involve a complete set of questions (such as a questionnaire), the difference being that the face to face situation allows the opportunity to expand, or clarify, the questions.
What is an aim
The general purpose of an investigation
What is stereotyping
Means developing an idea about someone and carrying that idea forward to apply it to other similar people
What is prejudice
Acting differently towards someone based on skin colour, gender, age
What is discrimination
Acting on prejudiced, through verbal or physical actions
