Research Methods - Research Methods (1-4) Flashcards
What are the different types of variables? (5)
Describe in detail
The Independent Variable (IV)
This is the variable that the researcher manipulates in order to determine its effect on the dependent variable. The independent variable may be divided into levels, sometimes referred to as experimental conditions.
An example might be that we want to investigate how chocolate (IV) effects mood.
The experimental conditions might be 10 grams of chocolate, 20 grams of chocolate and NO chocolate (see below)
Control condition
To provide a standard against which experimental conditions can be compared, there may be a control condition where the IV is not manipulated at all e.g. no chocolate and the effect on mood
The Dependent Variable (DV)
This is the variable that is being measured (mood)
Extraneous Variables (EV)
These are any variables other than the IV that COULD affect the DV.
Confounding Variables (CV)
These are any variables (other than the IV) that HAVE affected the DV. Examples include light and noise
Define operationalisation
For an experiment to be successful, the dependent and independent variables must be operationalised, therefore the variables need to be defined and stated how it will be measured. For example, if measuring aggression in children this must be defined and measured, e.g. ”Aggression means how angry or irritated a person is and this can be measured by displays of verbal or physical acts of aggression in a 10 minute period”
State the different types of experiment
- laboratory
- field
- quasi
- natural
Describe laboratory experiments in detail
- the experiment is carried out in a controlled environment e.g a laboratory, allowing the researcher to exert a high level of control over the IV and eliminate any EV.
- the researcher can then observe and measure the change in the DV caused by their manipulation of the IV.
- Participants (people who take part in psychological research) are randomly allocated to a condition. This means neither the experimenter nor the participants decides which condition the participant is placed in, an unpredictable method (such as flipping a coin) is used to decide.
- The other variables that an experimenter wants to hold constant are called extraneous variables. The aim of controlling EVs is to minimize their possible impact on the results of the investigation e.g participant’s personality or personal experiences
- Laboratory experiments are conducted in an artificial setting.
What are the advantages of a laboratory experiment
- very high level of control over the IV and conditions. Therefore it is very easy to control for any extraneous variables and prevent them from becoming confounding variables which might affect the measurements or data collected.
- the researcher can manipulate the independent variable and can establish a cause and effect relationship between the independent variable and the dependent variable.
- a laboratory experiment can be easily replicated (conducted again) by other researchers to see if similar results can be obtained. If the findings are similar to the original study than the results are reliable
What are the disadvantages of a laboratory experiment
- demand characteristics might occur within the study. This is where the participants in the study might guess what the aim of the study is and therefore change their behaviour accordingly which means the data becomes invalid. Some participants behave in a more positive light than normal and this can be called, social desirability bias
- establishing a high level of control over the independent variables and extraneous variables, means that the experimental situation can often lack mundane realism (the extent to which an experiment reflects real life). This means the laboratory study does not have ecological validity (the ability to generalise the findings of a piece of research to real life situations or other places/contexts).
Describe field experiments in detail
This is an experiment carried out in the real world or in a natural setting rather than in the artificial setting of a laboratory. The independent variable is still manipulated or controlled by the researcher to see the effect on the dependent variable. An example might be to observe people in the street.
What are the advantages of field experiments?
- there is more mundane realism and ecological validity than in a laboratory, and it reflects real life more than a laboratory experiment.
- because the researcher can manipulate the independent variable; a cause and effect relationship between the independent and the dependent variable can be established.
- there is less chance of demand characteristics as opposed to a laboratory experiment. In a field experiment the participants might not even be aware that they are taking part in research and so they will behave more naturally and more valid data will be collected
What are the disadvantages of field experiments
- there is less control over extraneous variables when compared to a laboratory experiment. Therefore the effect on the dependent variable may not be caused by the independent variable but by extraneous variables. This means the research is not valid (it is not measuring what it intends to measure).
- there is less control over the sample (this is who is taking part in the experiment). Therefore the sample might not be very representative of the target population.
- they might be difficult to replicate which means that they might be unreliable, especially when compared to laboratory experiments.
Describe in detail natural experiments
- the researcher takes advantage of a naturally occurring independent variable to see its effect on the dependent variable
- A natural experiment is a study that measures variables that aren’t directly manipulated (caused) by the experimenter, e.g. comparing behaviour in a single-sex and mixed school.
- This means that the independent variable is naturally occurring.
- the experimenter is finding participants who already meet the conditions of the experiment, rather than allocating participants to conditions themselves.
Why are the advantages of natural experiments
- there is a high level of mundane realism and ecological validity compared to laboratory experiments.
- they are very useful when it is impossible or unethical to manipulate the independent variable/sample in a laboratory or field experiment. E.g. psychologists wish to study a naturally occurring event which would otherwise be unethical to impose on participants e.g. a group of naturally stressed men aged 60-65 who have high stress levels and cholesterol.
What are the disadvantages of natural experiments?
- there is low control over extraneous variables compared to a laboratory experiment
- they are very difficult to replicate This means that they often are very unreliable and if the experiment was repeated, it is very unlikely that the same results would be gained again.
- they are difficult to determine cause and effect due to low levels of control.
Describe Quasi experiments in detail
- Quasi-experiments contain a naturally occurring independent variable but in a quasi-experiment the naturally occurring independent variable is a difference between people that already exists (i.e. gender, age).
- the researcher examines the effect of this variable on the dependent variable (DV).
- e.g. males have higher levels of testosterone than females in a sample of 50 men and 50 women aged 40-70. The psychologists might want to study this natural difference between the two genders and see what effect it might have on the dependent variable (aggression levels)
- Quasi experiments usually take place in a laboratory setting.
What are the advantages of quasi experiments?
- high level of control. The effects of extraneous variables are minimized, so the experimenter can be more confident that is the independent variable which has affected the dependent variable.
- replication is very likely. Due to strict controls this means it is easier to replicate the study to test reliability of findings.
What are the disadvantages of quasi experiments?
1) Lack of ecological validity because the setting is artificial experiments may not be a reflection of real-life behaviour.
2) Demand characteristics might be a problem. The participants may either accurately or inaccurately guess the aim of the experiment and respond according to what they think is being is investigated. This can affect the data collected and the results of the study (invalid).
What is an observation?
An observation is when a researcher watches or listens to participants engaging in whatever behaviour is being studied.
What are 2 ways psychologists can organize observations and collect the required observational data. How can they be sure that they do not miss any vital information?
- record the data either by making written notes or by video/audio recording the experiment. This is. Permanent record
- categorising behaviour: you must define behavioural categories you observe. Operationalise it. When observing egression categorise into hitting swearing shouting
What s non-participant observation?
This is when the researcher does not get directly involved with the interactions of the participants and does not take part in their activities. For example observing participants in the gym and the psychologist stands around and does not actually engage in any exercise.
What is an advantage and disadvantage of non-participant observation?
- Advantage: can focus on the activity occurring and can make good quality notes. More details recorded and nothing missed
- disadvantage: the researcher may look out of place and hence must make an effort to blend in so participants don’t guess they’re being watched
- disadvantage: the researcher wont have a deep understanding f participants behaviours so lack of validity
Describe participant observation
This is when the researcher is directly involved with the interactions of the participants and will engage in the activities that the participants are doing e.g. observing participants in the gym and the psychologist actually engages in exercise and uses the gym equipment
State some advantages and disadvantages of participant observation
- advantage: greater validity than non- participant observation as researcher gets involved in the activity and has a deeper understanding
- disadvantage: researcher may lose objectivity and become subjective as they are too involved in the activity also known as the researcher going native