Psych

ffffThe Research Methods Matrix Vocabulary list: Sampling procedures Sample: A sample is a subsection of research participants selected from a larger group of research interest. If the sample is selected in a scientific way, the results obtained for the sample can then be generalised to the larger group of research interest, called the population. Representative sample: A sample that is approximately the same as the population from which it is drawn in every important participant characteristic. There are different ways of obtaining a sample that is considered to be representative. Two ways are called random sampling and stratified sampling. Random sampling: A sample procedure that ensures that every member of the population of research interest has a genuinely equal chance of being selected as a participant for the research study. An example of obtaining a list of all the people in the population is called a sampling frame. For example, an electoral roll or telephone numbers of all the people in the particular location may be used. Stratified sampling: It involves dividing the population to be sampled into different subgroups or strata (area, age, sex, income level, ethnic or cultural backgrounds) then selecting a separate sample from each subgroup (called stratum) in the same proportions as they occur in the population of interest. Random-stratified sampling: When random sampling is used to select a sample from each stratum, it is called random-stratified sampling. To obtain a random stratified sample, the researcher must obtain accurate lists of all the people within each stratum, and then the researcher will draw a random sample of proportionate size from each of the strata. Random allocation: Participants selected for the experiment are just as likely to be in the experimental group as the control group. This means that every person who will be a participant in the experiment has an equal chance of being selected in any of the groups used. Advantages and Limitations of experimental research Advantages | Limitations | * The IV can be manipulated in order to observe the effect on the DV, therefore making it possible to test if there is a cause and effect relationship between the IV and DV. * The experimenter can report the conditions of an experiment in such a precise way that others can replicate the experiment and test the results. * The researcher can determine the cause and effect of a study. An example could be whether or not nicotine affects ones driving abilities. * It can be used to determine what is best for the population. * Variables can be controlled easily. * The experiment is taken in a highly controlled environment. * Choice of participants can be random. | * It is often difficult to strictly control all variables because of the unpredictability of real-life settings. * It may be difficult for participants to express their emotions naturally or very realistically in a laboratory setting. * It doesn’t provide individual information. * Results may only apple to one situation and may be difficult to replicate. * The groups may not be comparable. * Low in ecological validity. | Popular data collection techniques used in psychological research Statistical survey A method used to collect in systematic way information from a sample of individuals. A survey may focus on different topics such as preferences (e.g., for a presidential candidate), behaviour (smoking and drinking behaviour), or factual information (e.g., income), depending on its purpose. There are several ways of administering a survey, the most common are: telephone, mail, online surveys, personal in-home survey and personal mall intercept survey. The advantages of statistical surveys are that they are easy to administer and a large area can be covered under survey in the available time and money. The disadvantages are that they depend on subjects’ motivation, honesty, memory, and ability to respond. Self report inventory  Self-report inventory is a type of psychological test in which a person fills out a survey or questionnaire with or without the help of an investigator. It often asks direct questions about symptoms, behaviours, and personality traits associated with one or many mental disorders or personality types in order to easily gain insight into a patient's personality or illness The biggest problem with self-report inventories is that patients may exaggerate symptoms in order to make their situation seem worse, or they may under-report the severity or frequency of symptoms in order to minimize their problems. For this reason, self-report inventories should be used only for measuring for symptom change and severity and should never be solely used to diagnose a mental disorder. Scientific control Scientific controls ensure that data are valid, and are a vital part of the scientific method. An experiment which uses controls is called a controlled experiment, and usually separates research subjects into two groups: An experimental group and a control group. The control group is practically identical to the treatment group, except for the single variable of interest whose effect is being tested. An example of control is testing a drug, it is important to carefully verify that the supposed effects of the drug are produced only by the drug itself. Positive controls confirm that the procedure is competent in observing the effect (therefore minimizing false negatives). Negative controls confirm that the procedure is not observing an unrelated effect (therefore minimizing false positives)