Experimental Method

Question 1

What is the IV?

What is the DV?

Answer 1

IV- Change

DV- Measure

Question 2

What is an aim?

Answer 2

An aim is the general investigative purpose of the study.

Question 3

What is an experimental / alternative hypothesis (H1)?

Answer 3

H1 is a testable, predictive statement that says that something will happen.

Question 4

A H1 can be?

Answer 4

H1 can be directional or non-directional.

Question 5

Whats a directional hypothesis?

What does it words does it contain?

Answer 5

A directional hypothesis (also known as a one-tailed hypothesis) is very precise and tells us exactly what the researcher thinks will be found.

Directional hypotheses therefore tend to contain words like ‘higher or lower’, ‘more or less’, ‘bigger or smaller’ etc.

For example:
“participants who are given coffee to drink are significantly more talkative than those who are not.”

Question 6

Whats a non-directional hypothesis?

What words does it contain?

Answer 6

A non-directional hypothesis (also known as a two-tailed hypothesis) predicts that there will be some effect or difference seen, but does not specify exactly what that effect or difference will be.

Non-directional hypotheses therefore tend to contain words like ‘there will be a significant difference’.

For example:
“there will be a significant difference in how talkative people who have coffee and people who do not have coffee are.”

Question 7

What is a null hypothesis?

Answer 7

We also need a null hypothesis (h0).

This says that nothing will happen – there will be no significant difference between the two groups in the experiment.

For example:
“there will be no significant difference between how talkative people who have coffee and people who do not have coffee are. Any difference found will be due to chance.”

Question 8

How do we test the effect of the IV?

Answer 8

In order to test the effect of the IV, we need different groups to compare – one group who experiences the IV and one who does not.

Question 9

What are the two levels of the IV?

Answer 9

The control condition

The experimental condition

Question 10

What does operationalise variables mean?

Answer 10

To operationalise variables means to define variables in a form that can be easily measured and tested.

For example, a concept such as ‘being talkative’ needs to be specified more exactly if we are going to measure it. So ‘being talkative’ can be measured in terms of how many words a person says in, for example, 5 minutes.

Question 11

Whats cause and effect?

Answer 11

Unwanted factors that can potentially affect the relationship between the iv & the dv, spoiling or distorting the cause & effect relationship and threatening the validity (truthfulness) of the research

Question 12

What are 4 unwanted factors?

Answer 12

Demand characteristics
Confounding variables
Extraneous Variables
Instigator effects

Question 13

What is an extraneous variable?

Answer 13

An extraneous variable (EV) is any variable, other than the IV, that may affect the DV if we do not control for it.

They are ‘nuisance’ variables; unwanted and extra variables.

They do not vary systematically with the IV. This is a fancy way of saying EVs could affect participants in either condition of the experiment.

Question 14

What can EVs be subdivided into?

Answer 14

EVs can be subdivided into participant variables and situational variables.

Participant variables
Situational variables

Question 15

What are situational variables?

Answer 15

Situational variables refer to things to do with the environment the research is carried out in that could affect the DV.

Question 16

What are participant variables?

Answer 16

Participant variables refer to things to do with the participant that could affect the DV.

Question 17

Most EVs can be managed by?

You may choose to run?

Answer 17

In general, most EVs (both participant and situational) can be managed with ambit of good planning and thinking ahead about what EVs might be present in your research

You may choose to run a pilot study, which is a small-scale trial of the actual investigation.

Question 18

What will a pilot study allow you to do?

Answer 18

This will allow you to identify any potential EV issues that you may not have thought of, e.g. the room you are doing the research in is very noisy because of building work, and in turn modify the design or procedure.

Question 19

How to control situational variables?
This means that all participants are subject to the same?
This controls the?

Answer 19

Situational variables are controlled using standardised procedures.

This means that all participants are subject to the same environment, information and experience (including the same instructions for the task).

This controls the environment and ensures that all participants are tested under the same conditions (situation).

Question 20

How to deal with participant variables?

Answer 20

Use the same participants in both conditions
Use different but matched participants in each condition
Use different participants in each condition but randomly allocate participants to each condition

Question 21

What are confounding variables?

Answer 21

A confounding variable (CV) is a variable that is not the IV but could end up being a second, unintended IV for some (not all) participants.

For example to go back to our coffee example where we were seeing if the IV (coffee) could affect our DV (talkativeness).
Imagine that I had sent the experimental group to the canteen to get coffee while I kept the control group in a separate room because they didn’t need to have a drink.

Question 22

Why is it harder to control for CVs?

Answer 22

It is much harder to control for CVs. It is more likely that you would consider them in the discussion of your research once it has been carried out.

But while they were in the canteen somebody ran in and threatened the staff with a knife.
When the group gets back to the experiment with their coffee, they are all going to be talking about this and this unexpected event means we have ended up with a second, unintended IV of the emotion and experience of being caught up in this event.

This makes it very hard for us to decide whether any increase in the DV of talking is due to the intended IV (the coffee) or the unintended IV (witnessing the robbery and the emotion this produced).

Question 23

What are demand characteristics?

Answer 23

Most participants in an experiment will be spending time trying to make sense of what is going on and what the researcher is investigating.

Therefore they may look for cues (clues) to help them interpret what is happening and the participants may use the cues to try and ‘second guess’ the researcher’s intentions and the aim of the research and how they should behave. These cues are known as demand characteristics.

Question 24

What can demand characteristics result in?

Answer 24

Demand characteristics can result in participants showing:

The ‘please you’ effect where they act in the way that they think is expected

The ‘screw you’ effect where they deliberately underperform to sabotage the results of the study

Either way, participant behaviour is no longer natural.

Question 25

What is one way to deal with demand characteristics?

Answer 25

One way to deal with demand characteristics is to use what is known as a single-blind procedure.

In a single-blind procedure information will be kept from the participant at the start of the study, e.g. the aim of the research, its hypothesis, what the conditions of the study are, which condition they are in etc.

This is an attempt to ensure that any information that might create expectations in the participants are not revealed until the end (when it should be revealed for ethical reasons).

Question 26

When do investigator effects occur?

How do they occur through non verbal communication?

Answer 26

Investigator effects occur when a researcher unintentionally or unconsciously influences the outcome of any research they are conducting.

This could be done in several ways, e.g.
Non-verbal communication in which the researcher communicates their feelings about what they are observing without being aware they have done so. For example, raising an eyebrow which might make a participant aware they have said or done something which has surprised or shocked the researcher and so they might change their response.

Question 27

What are 2 other ways investigator effects occur?

Answer 27

Bias in interpretation of data where the researcher interprets the data in a way that fits in with their expectations

Physical characteristics of the researcher, e.g. their appearance or gender, which might influence the behavioural response of the participant.

Question 28

What is one way to deal with investigator effects?

Answer 28

One way to deal with investigator effects is to use what is known as a double-blind procedure.