Hypothesis testing and errors key words

Question 1

Null hypothesis definition

Answer 1

Predicts there will be no significant difference/relationship between 2 sets of results. States any significant result due to chance factors

Question 2

Experimental hypothesis definition

Answer 2

Predicts there will be a significant difference or relationship between 2 sets of results gathered via controlled conditions in which the investigator has manipulated the variable(s)

Question 3

Alternative hypothesis definition

Answer 3

Predicts that there will be a significanct difference or relationship between 2 sets of results not gathered via controlled conditions in which the investigator has manipulated the variable(s)

Question 4

Variable definition

Answer 4

Something which can differ, or vary, from one situation to another or from one person to another. So factors such as, intelligence, the number of dreams a person has, age, health, and extraversion are all examples

Question 5

Operationalised definition

Answer 5

To make something measurable. For example, if you wanted to test intelligence you would make it measurable by administrating an IQ test and comparing the scores.

Question 6

Type I error definition

Answer 6

Occurs when we reject the null hypothesis when, in fact the results are due to chance. This can happen because of poor exxperimental design, confounding variables, or setting too lax a significance level

Question 7

Type II error definition

Answer 7

Occurs when we accept the null hypothesis when, in fact the results are significant. This can happen because of poor experimental design, faulty sampling, random error or setting too stringent a significance level

Question 8

1-tailed hypothesis definition

Answer 8

Predicts the direction of the difference or relationship between 2 sets of results, therefore it is believed the results will only be in 1 direction or tail of a normal distribution

Question 9

2-tailed hypothesis definition

Answer 9

Predicts a difference but does not predict the direction or relationship between 2 sets of results and allows for the possibility that the difference could be in either direction, this means there is double the probability that the results could occur by chance

Question 10

Objective definition

Answer 10

To test or make judgements free of emotion or personal experience. What scientific methods aim to be

Question 11

Probability definition

Answer 11

Likelihood of event occurring, can be expressed as a % or decimal figure. Calculated by number of particular outcomes/number of possible outcomes

Question 12

Significance level definition

Answer 12

Level of probability set by psychologists that results are due to experiment, not chance factors. Accepted level = 0.05