Research methods Flashcards
Experimental method definition
Involves the manipulation of an independent variable (IV) to measure the effect on the dependent variable (DV). Experiments may be laboratory, field, natural or quasi.
Aim definition:
a general statement of what the researcher intends to investigate, the purpose of the study.
hypothesis definition
A clear, precise, testable statement that states the relationship between the variables to be investigated. Stated at the outset of any study.
directional hypothesis definition
States the direction of the difference or relationship.
Non directional hypothesis definition
Does not state the direction of the difference or relationship.
Variables definition
Any ‘thing’ that can vary or change within an investigation. Variables are generally used in experiments to determine if changes in one thing result in changes to another.
Independent variable definition
Some aspect of the experimental situation that is manipulated by the researcher - or changes naturally - so the effect on the DV can be measured.
Dependent variable definition
(DV) The variable that is measured by the researcher. Any effect on the DV should be caused by the change in the IV.
operationalisation definition
Clearly defining variables in terms of how they can be measured.
Experimental method aims (AO1)
theory that energy drinks affect how much people talk based on understanding (having read a few research studies on the Internet) that energy drinks contain sugar and caffeine, and that these substances increase alertness, making people chattier
a new energy drink - SpeedUpp - is tested to know whether it might affect the talkativeness of those who drink it.
- then produce an aim which are developed from theories, like our energy drink theory, except they tend to be much more sophisticated and are based on many more hours of research!
Aims are general statements that describe the purpose of an investigation.
the aim would be something along the lines of:
To investigate whether drinking energy drinks makes people more talkative.
hypothesis (AO1)
A hypothesis is a statement that is made at the start of a study and clearly describes the relationship between variables as stated by the theory.
e.g Drinking SpeedUpp causes people to become more talkative.
Hypotheses can be directional or non-directional. In a directional hypothesis the researcher makes clear the difference that is anticipated between two conditions or two groups of people. For this reason, directional hypotheses include words like more or less, higher or lower, faster or slower, etc.
People who drink SpeedUpp become more talkative than people who don’t.
People who drink water are less talkative than people who drink SpeedUpp.
A non-directional hypothesis states there is a difference between conditions or groups of people but, unlike in a directional hypothesis, the nature of the difference is not specified.
People who drink SpeedUpp differ in terms of talkativeness compared with people who dont drink SpeedUpp.
doing an experiment (AO1)
energy drink test done by experimental method. First gather together two groups of people, e.g ten in each group. Then, starting with the first group, we will give each person (or each participant - because that’s what you call people in studies a can of SpeedUp to drink.
- participants in other group will just have a glass of water each. then record how many words each participant says in a five-minute perio immediately after they have had their drink.
Deciding which hypothesis to use (AO1)
we are taking the whole design process slowly) and the exact details of how it would work, which type of hypothesis should we choose?
Researchers tend to use a directional hypothesis when a theory or the findings of previous research studies suggest a particular outcome. When there is no theory or previous research, or findings from earlier studies are contradictory, researchers instead decide to use a non-directional hypothesis.
Even though SpeedUpp is a new energy drink, the effects of caffeine and sugar on talkativeness are well-documented. so we will opt for a directional hypothesis on this occasion.
Independent and dependent variables (AO3)
researcher changes or manipulates the independent variable (IV) and records or measures the effect of this change on the dependent variable (DV). other variables that might potentially affect the DV should remain constant in a properly run experiment. researcher can be confident that any change in the DV was due to the IV, and the IV alone.
Levels of the IV (AO3)
to test the effect of IV we need different experimental conditions. If we gave some participants SpeedUpp, how would we know how talkative they were? We need a comparison. We could:
• Compare participants’ talkativeness before + after drinking SpeedUpp.
• Compare two groups of participants - those who drink SpeedUpp with those who drink water
- the two conditions: no SpeedUpp or drinking SpeedUpp.
These are the two levels of the IV: the control condition (no SpeedUpp / drink of water) and the experimental condition (energy drink).
well-written hypothesis: easy to tell what the IV and DV are. directional hypothesis example:
The group that drinks an energy drink will be chattier than the group that drinks water.
- correct as long as they state the operationalised variables and the relationship between them.
Operationalisation of variables (AO3)
and operationalise the variables in the hypothesis in order to make it testable.
e,g social behaviour, intelligence or thinking, are often a little fuzzy and not easy to define. Thus, in any study, one of the main tasks for the researcher is to ensure that the variables being investigated are clear + measurable
e.g After drinking 300 ml of SpeedUpp, participants say more words in the next five minutes than participants who drink 300 ml of water.
Extraneous variable (EV) definition:
Any variable, other than the independent variable (IV), that may affect the dependent variable (DV) if it is not controlled. EVs are essentially nuisance variables that do not vary systematically with the IV.
Confounding variables definition:
A kind of EV but the key feature is that a confounding variable varies systematically with the IV. Therefore we can’t tell if any change in the DV is due to the IV or the confounding variable.
Demand characteristics definition:
Demand characteristics Any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of an investigation.
This may lead to a participant changing their behaviour within the research situation.
Investigator effects definition:
Investigator effects Any effect of the investigator’s behaviour (conscious or unconscious) on the research outcome (the DV). This may include everything from the design of the study to the selection of, and interaction with, participants during the research process.
. Randomisation definition:
The use of chance methods to control for the effects of bias when designing materials and deciding the order of experimental conditions.
Standardisation definition:
Using exactly the same formalised research study.
procedures and instructions for all participants in a
Extraneous variables (AO1)
The key to an experiment is that an inderandent V. ial enV is manipulated (changed) to see how this affects the dependent variable tential iny thing that should influence the DV is the IV. Any other variables that might potentially interfere with the IV or the DV) should be controlled or removed. These additiona, unwanted variables are called extraneous variables and, where possible, are identified at the start of the study by the researcher, who then takes steps to minimise their influence.
Many extraneous variables are straightforward to control such as the age of the participants, the lighting in the lab, etc. These are described as nuisance variables’ that do not vary systematically with the IV. These may muddy the experimental water so to speak but do not confound the findings of the study. They may just make it harder to detect a result.
Confounding variables (AO1)
do change systematically with the IV. Let us imagine in our energy drink study we have twenty participants in total and decide to use the first ten participants who arrive for the Speedupp condition. It happens that these first ten participants are all very excited because they saw Prince William arrive at their school.
This meant that there was some delay before further participants arrived and by then people were less excited. This unexpected event means we have ended up with a second unintended IV - being excited or not.
So when we come to analyse our results and find that the Speedupp group were chattier we can’t be sure if this is because of the drink or the excitement. The problem is that the emotion varied systematically with the IV and this alone could explain changes in the DV.