Research Methods Flashcards
What are the measures of central tendency?
Mean
Median
Mode
What is the Mode?
Calculates the most frequent score in a data set. The mode is the value that occurs most frequently.
What is the Median?
The middle number within an ordered set of values
What is the Mean?
The middle number within an ordered set of values
What type of data is the mode, median and mean typically used for?
Mode - Nominal
Median - Ordinal
Mean - Interval/Ratio Level
What are the levels of measurement from lowest to highest? Explain them
Nominal data- frequency count data
Ordinal- scores in rank order
Interval- a continuous scale with no absolute zero
Ratio- a continuous scale with an absolute zero
What is a null hypothesis, what is an experimental hypothesis?
How is a null hypothesis tested?
Null- The experimenter predicts the IV will have no effect on the DV/ no significant effect will be found
Experimental- The experimenter predicts the IV will have an effect on the DV/ a significant effect will be found
It is tested by ?
What is a one-tailed directional, and a two-tailed non-directional hypothesis?
A one-tailed directional hypothesis predicts the nature of the effect of the independent variable on the dependent variable.
E.g., adults will correctly recall more words than children.
Non-directional predicts that the independent variable will have an effect on the dependent variable, but the direction of the effect is not specified.
E.g., there will be a difference in how many numbers are correctly recalled by children and adults.
What are extraneous variables and confounding variables?
Extraneous- All variables, which are not the independent variable, but could affect the results (DV) of the experiment. EVs should be controlled where possible.
Confounding- Variable(s) that have affected the results (DV), apart from the IV. A confounding variable could be an extraneous variable that has not been controlled.
What are situational and participant variables?
the differing individual characteristics that may impact how a participant responds in an experiment. Examples of participant variables include gender, age, ethnicity, socioeconomic status, literacy status, mood, clinical diagnosis etc.
What are field and lab experiments and outline the strengths and weaknesses.
A laboratory experiment is an experiment conducted under highly controlled conditions (not necessarily a laboratory), where accurate measurements are possible.
The researcher decides where the experiment will take place, at what time, with which participants, in what circumstances and using a standardized procedure.
Participants are randomly allocated to each independent variable group.
Strengths:It is easier to replicate (i.e. copy) a laboratory experiment. This is because a standardized procedure is used.
They allow for precise control of extraneous and independent variables. This allows a cause and effect relationship to be established.
Weaknesses:The artificiality of the setting may produce unnatural behavior that does not reflect real life, i.e. low ecological validity. This means it would not be possible to generalize the findings to a real life setting.
Demand characteristics or experimenter effects may bias the results and become confounding variables.
Field experiments are done in the everyday (i.e. real life) environment of the participants. The experimenter still manipulates the independent variable, but in a real-life setting (so cannot really control extraneous variables).
Strength: behavior in a field experiment is more likely to reflect real life because of its natural setting, i.e. higher ecological validity than a lab experiment.
There is less likelihood of demand characteristics affecting the results, as participants may not know they are being studied. This occurs when the study is covert.
Weakness: There is less control over extraneous variables that might bias the results. This makes it difficult for another researcher to replicate the study in exactly the same way.
What are demand characteristics?
The clues in an experiment that lead the participants to think they know what the researcher is looking for (e.g. experimenter’s body language).
What are order effects and how do you get rid of them?
Changes in participants’ performance due to their repeating the same or similar test more than once. Examples of order effects include:
(i) practice effect: an improvement in performance on a task due to repetition, for example, because of familiarity with the task;
(ii) fatigue effect: a decrease in performance of a task due to repetition, for example, because of boredom or tiredness.
Identify and explain the types of research/experiment design
Matched pairs
An experimental design where pairs of participants are matched in terms of key variables, such as age or socioeconomic status. One member of each pair is then placed into the experimental group and the other member into the control group.
One member of each matched pair must be randomly assigned to the experimental group and the other to the control group.
Independent group
An experimental design where different participants are used in each condition of the independent variable. This means that each condition of the experiment includes a different group of participants.
This should be done by random allocation, which ensures that each participant has an equal chance of being assigned to one group or the other.
Independent measures involve using two separate groups of participants; one in each condition.
Repeated measures
An experimental design where the same participants take part in each condition of the independent variable. This means that each condition of the experiment includes the same group of participants.
Counterbalancing is done in this method.
The sample would split into two groups experimental (A) and control (B). For example, group 1 does ‘A’ then ‘B,’ group 2 does ‘B’ then ‘A’ this is to eliminate order effects. Although order effects occur for each participant, because they occur equally in both groups, they balance each other out in the results.
Explain why it is helpful to have a control group.
Scientists use controlled experiments because they allow for precise control of extraneous and independent variables. This allows a cause and effect relationship to be established.
Unlike the experimental group, the control group is not exposed to the independent variable under investigation and so provides a base line against which any changes in the experimental group can be compared.