Unit 4 Flashcards
What are the principles of the Selection of Participants?
Who are they?
How many are needed?
Where are they located?
How will they be selected?
What are researchers in psychology usually interested in?
drawing conclusions about some very large group of people
How do we call a very large group of people in research?
population
e.g.: American teenagers, children with autism, professional athletes, etc.
What is usually studied in the population?
only a small subset or sample of the population
What does representative mean in relation to the sample size?
sample is representative when it is a good reflection of a wider population and when the results derived from the experiment can be GENERALIZED to the population of interest
What are the three principles of participant selection?
Suitability, Accessibility, Sample Size
What does Suitability mean in the selection of participants? What does it refer to?
inclusion and exclusion criteria including any restrictions based on demographic characteristics
-> refers to how well the chosen participants match the characteristics needed to answer the research questions
What are demographic characteristics?
specific attributes of individuals that are often used to classify populations in research
-> include age, gender, race, ethnicity, occupation, marital status, geographic location
What does the sample size determine?
the number of experimental units or subjects required, based on statistical methods and specify the procedure, usually randomized, to assign subjects to the experimental conditions
What is a common critique of experiments in a study?
that a study did not have enough participants
-> difficult to generalize about population from a small sample
What is a power analysis?
calculation when designing a study, that determines the number of participants you need to recruit to detect an effect of a specific size
what is critical and essential to adequately design a study?
the sample size
What does Hypothesis Testing include?
H0 - Null hypothesis (no difference between study group)
H1 - Alternative hypothesis (There IS a difference between study groups)
Which values are ideal for a good study?
a high power value
-> elevated chance of detecting a difference between groups (confirm the H1)
What is Power value?
a percentage between 0 and 100%
-> it is a probability
What increases when sample size increases?
power
-> when too low, low probability of rejecting the null hypothesis
What is Power in sample size referred to?
Power is the probability of correctly rejecting the nullhypothesis when the null hypothesis is false
-> power reflects the likelihood of detecting a true effect in the underlying population when such an effect exists
What kind of value is excepted for a power value?
80%
What does procedure refer to in the methods section of a research paper?
to the step-by-step description of how the study was conducted
What does Accessibility Sampling Procedures refer to?
the methods and considerations involved in selecting participants for a research study
-> ensures that sample is appropriate for study goals
Which 2 types of sampling are there?
- Probability sampling
- Non-probabililty sampling
When does probability sampling occur?
when the researcher can specify the probability that each member of the population will be selected for the sample
When does non-probability sampling occur?
when the researcher cannot specify these probabilities. Most psychological research involves non-probability sampling
What is a common form of non-probability sampling?
Convenience sampling - studying individuals who happen to be nearby and willing to participate
What does probability sampling require?
a sampling frame
What is a sampling frame
it is a specific list, database or set of elements from which a sample is drawn for a research study
-> defines population of interest
What is simple random sampling?
every member of the population has an equal chance of being selected for the sample
What is a difficulty in random sampling in psychological research?
the populations are less clearly defined than the registered voters in a city
What are the 4 main ways to conduct surveys?
in-person interviews
by telephone
through the mail
on the internet
What is a Survey?
A research tool that is used to ask people to tell us about themselves
What are the 2 most common survey techniques?
Interviews
Questionnaires
What is Quota Sampling?
A non-probability sampling method where researchers divide the population into subgroups (strata) based on specific characteristics, then select participants from each subgroup to meet a predefined quota
What is judgmental sampling?
a non-probability sampling technique where the researcher selects participants based on their knowledge, expertise, or judgment about who will provide the most useful information for the study
What is a synonyme for judgemental sampling?
purposive sampling
What are costs related to simple random sampling?
Making the list
Picking randomly
Reaching the people you pick
Handling non-responses
Keeping things organized
What does the choice between simple random sampling and systematic sampling depend on?
the research goals, population characteristics, and available resources
What is systematic random sampling?
an efficient and structured method for selecting a sample,
especially when a complete list of the population is available
What are the key differences between random sampling and systematic random sampling?
- Random Sampling uses a purely random approach for every selection.
- Systematic Random Sampling relies on intervals and an initial random start.
What is Cluster sampling?
every member of the population is assigned to one, and only one, group. Each group is called a cluster. A sample of clusters is chosen, using a probability method (often simple random sampling). Only individuals within sampled clusters are surveyed
What is stratified sampling?
the population is divided into subgroups or “strata”, based on some characteristic. Then, within each group, a probability sample (often a simple random sample) is selected. In stratified sampling, the groups are called strata
What is the difference between stratified sampling and cluster sampling?
With stratified sampling, the sample includes elements from each stratum. With cluster sampling, in contrast, the sample includes elements only from sampled clusters.
What is convenience sampling?
a non-probability sampling technique where participants are selected based on their availability, proximity, or ease of access to the researcher, rather than through a random or systematic selection process.
What are the 4 sampling strategies of probability sampling?
Simple random sampling
Systematic sampling
Cluster sampling
Stratified sampling
What are the 3 sampling strategies of non-probability sampling?
Judgement sampling
Convenience sampling
Quota sampling
Besides survey techniques, what are 2 ways of data collection?
Observation
Performance test
What is a common and important method of studying
behavior?
Surveys
What should the questions in a questionnaire be like?
relatively simple
Which 2 types of questions are there in a questionnaire?
Closed-ended questions
Open-ended questions
What does the interviewer use in a structured interview?
a set of prepared, closed-ended questions that are read exactly as worded. Structured interviews follow a standardized format, meaning the same questions are asked to each interviewee in the same order
What are structured interviews mainly associated with?
Quantitative research
What does the interviewer do in an unstructured interview?
does not follow specific guidelines, restrictions, predetermined questions, or a set list of options. Instead, the interviewer begins with a few broad, open-ended questions to initiate an informal and spontaneous discussion
What is the Likert Scale?
a psychometric scale in which responses are scored along a range, measuring either positive or negative response to a statement
-> Common pattern:
1. Strongly disagree, 2. Disagree, 3. Neither agree nor disagree
4. Agree, 5. Strongly agree
What are examples for latent traits, health component, attitudes, preferences, behaviors and facts?
Latent traits (e.g. personality traits such as extroversion)
health component (e.g. sleep, mood)
attitudes (e.g.
towards immigration)
index (e.g. Social Economic Status)
preferences (e.g. political party)
behaviors (e.g. food
consumption)
facts (e.g. gender)
What can open-ended questions not be answered with?
A simple yes or no
What is a performance test?
An assessment that requires the examinee to perform a task or activity directly, rather than merely answering
questions about specific components. This approach aims to ensure greater fidelity to the skills or abilities being
tested
What are performance psychometric tests?
Standardized measures of a particular psychological variable such as intelligence, attention or other executive functions
What does one-dimensional and multi-dimensional stand for in the internal structure?
- One-dimensional: measures a single factor, gives a total score
- Multidimensional: measures several factors, gives several scores
What is internal consistency?
a measure of how well the items (questions or components) within a test, survey, or scale are related to each other and contribute to measuring the same construct (underlying idea or concept)
What is Cronbach‘s Alpha?
a critical tool in research and testing to ensure scales and questionnaires are
reliable
-> indicates how well the items in a scale measure the same underlying concept
or construct
