EXPERIMENTAL METHOD Flashcards
What is an experimental method?
Experimental methods involve the manipulation of an independent variable to measure the effect on the dependent variable. Experiments may be laboratory, field, natural or quasi.
In psychological research, aims are developed from theories. What is an aim?
An aim is a general statement of what the researcher intends to investigate: the purpose of the study.
A psychologist has a theory that energy drinks affect how much people talk. In this context, would would the aim be?
The aim would be ‘to investigate whether drinking energy drinks makes people more talkative’.
What is developed following the formulation of the aim?
Having written an aim, a psychologists needs to formulate a hypothesis.
What is a hypothesis?
A hypothesis is a clear, precise, testable statement that states the relationship between the variables being investigated. The hypothesis is stated at the outset of any study.
Using the context of the energy drink experiment, provide an example of a hypothesis.
‘Drinking SpeedUpp causes people to become more talkative’.
How many types of hypotheses are there?
There are two major types of hypotheses.
What are the two types of hypotheses?
- A directional hypothesis
- Non-directional hypothesis
What is a directional hypothesis?
In a directional hypothesis the researcher states the direction of the difference or relationship between two conditions. For this reason, directional hypotheses include words like more or less, higher or lower, faster or slower.
Using the context of the energy drink experiment, provide an example of a directional hypothesis.
‘People who drink SpeedUpp become more talkative than people who don’t’.
What is a non-directional hypothesis?
A non-directional hypothesis simply states that there is a difference between conditions of groups of people but, unlike in a directional hypothesis, the nature of the difference is not specified.
Using the context of the energy drink experiment, provide an example of a non-directional hypothesis.
‘People who drink SpeedUpp differ in terms of talkativeness compared with people who don’t drink SpeedUpp’.
Decide whether the following hypothesis is directional or non-directional: ‘There is a difference in children’s reading ability depending on whether they have blue or brown eyes’.
Non-directional hypothesis
Decide whether the following hypothesis is directional or non-directional: ‘Dogs that are rewarded with treats sit when told to do so more often than dogs that are not rewarded with treats’.
Directional hypothesis
Decide whether the following hypothesis is directional or non-directional: ‘There is a difference in the psychology grades of students depending on whether they are male or female’.
Non-directional hypothesis
Decide whether the following hypothesis is directional or non-directional: ‘Teenagers who watch horror films have more friends than teenagers who watch romantic comedies’.
Directional hypothesis
When do psychologists opt to use a directional hypothesis?
Psychologists tend to use a directional hypothesis when the findings of previous research studies suggest a particular outcome.
When do psychologists opt to use a non-directional hypothesis?
Psychologists tend to use a non-directional hypothesis when there is no previous research, or findings from earlier studies are contradictory.
In an experiment, what variable is changed or manipulated by the researcher?
In an experiment, a researcher changes or manipulates the independent variable (IV).
Within an experiment, the independent variable is changed or manipulated by the researcher. What is the IV?
The IV refers to some aspect of the experimental situation that is manipulated by the researcher. This allows the effect on the DV to be measured.
In an experiment, what variable is recorded or measured by the researcher?
The researcher records or measures the effect of change on the dependent variable (DV).
What is a dependent variable?
A dependent variable is the variable that is measured by the researcher. Any effect on the DV should be caused by the change in the IV.
Why is it important for a researcher to maintain a number of control variables?
This allows the researcher to be confident that the cause of the effect on the DV was the IV, and the IV alone.
What are the two levels of an independent variable?
- The control condition
- The experimental condition
In the energy drink experiment, what would the two levels of the IV look like?
In the control condition participants would be given a drink of water. In the experimental condition participants would be given the energy drink.
What is operationalisation?
Operationalisation refers to when psychologists clearly define variables in terms of how they can be measured.
