Ch 2: Types of Data, How to Collect Them & More Terminology Flashcards
What is a variable?
simply a characteristic or feature of the thing we are interested in understanding; it is a condition or characteristic that can take different values (ex. stress level, height, social class, score on a creativity test, number of people absent on a given day, anxiety levels, physical health etc.); anything we can count or measure
What is a value?
just a number or category(word), such as male and female, or a psychology diagnosis (major depressive disorder, post-traumatic stress disorder, schizophrenia)
What is a score?
each person studied has a particular one that is his or her value on the variable
What are the basic components to a statistical investigation?
- planning the study (asking a testable research question and deciding how to collect data)
- examining the data (what are appropriate ways to examine it and asking questions about the data)
- inferring from the data (what are valid statistical methods for drawing inferences “beyond” the data you collected?)
- drawing conclusions (based on what you learned from the data, what conclusions can you draw and who do they apply to?)
What is a population?
the entire group that a researcher wishes to study; can be quite large; the larger group of the sample
What is a sample?
a smaller more manageable group that is used to measure populations; they are the participants in the research; a set of individuals selected from a population; typically a small subset of the population; A subset of individuals selected from a population for study.
What is the difference between a population and a sample?
if data describes a sample it is a statistic
if data describes a population it is a parameter
What is a representative sample?
when the sample closely matches the population from which it was selected; A sample that accurately reflects the characteristics of the population from which it was drawn.
What is an unrepresentative (biased) sample?
a subject of the population that does not have the characteristics typical of the target population
What is random sampling (random selection)?
the ideal method of picking out a sample to study; first the researcher starts with a complete list of the population and selects some to study; is considered a fair way of selecting a sample from a given population since every member is given equal opportunities of being selected; this process also helps to ensure that the sample selected is more likely to be representative of the larger population; Selection method where every member of the population has an equal chance of being selected
What is sampling error?
if the sample is not representative of the population, the random variation is called this; The difference between a sample statistic and the true population parameter.
What is stratified random sampling?
since simple random sampling often does not ensure a representative sample, this sampling method is used to make the sample more representative of the population
What is convenience sampling?
often studies are conducted with whoever is willing or available to be a research participant-and is commonly referred to as this
What are WEIRD cultures?
96% of participants in psychology studies come from
Western
Educated
Industrialized
Rich
Democratic countries
What is observational studies?
information gathered by observing
What is an experimental design?
a researcher assigns or manipulates the group’s participants will be in; Research method involving manipulation of variables and random assignment to groups.
What is randomly assigned?
how each participant is assigned to a group
What is an independent variable?
when a variable is manipulated by an experimenter; The variable manipulated by the researcher in an experiment.
What is a dependent variable?
the effect caused by the independent variable; The outcome variable measured in response to the independent variable
What is the experimental (treatment) group?
the group who are exposed to the independent variable (or the manipulation) by the researcher;
What is a control group?
the group who are not exposed to the treatment variable; they serve as the comparison group; Group in an experiment that doesn’t receive the treatment/manipulation.
What is a quasi-experiment?
involves manipulating the independent variable
but not randomly assigning people to groups
What is an extraneous variable?
is something that occurs in the
environment or happens to the participants that
unintentionally (accidentally) influences the outcome of
the study; it affects everyone in the study
What is a confounding variable?
a type of extraneous variable
that changes at the same time as the independent
variable, making it difficult to discern which one is causing
changes in the dependent variable
What is operationalize?
The act of defining how to measure your data
What are qualitative variables?
Those that express an attribute such as hair color, eye color,
religion, favorite movie, gender, and so on; sometimes referred to as
categorical variables
What are quantitative variables?
those variables that are measured in terms of numbers; some examples are height, weight, and shoe size
What are discrete variables?
Variables such as number of children in a household, example a household could have three children or six children, but not 4.53 children
What are continuous variables?
Other variables such as “time to respond to a question”, the response time could be 1.64 seconds, or it could be 1.64237123922121 seconds
What are levels of measurement?
Numbers mean different things in different situations; demonstrate the relationship between the questions we ask, and what the answers to
those questions can tell us; in a given category, all of the procedures share some properties that are important for you to know about; The
categories are called “scale types,” or just “scales,”
1. Nominal scales (one simply names or categorizes responses ex gender, handedness, favorite color, & religion)
2. Ordinal scales (The items in this scale are ordered, ranging from least to most satisfied)
3. (Equal) Interval scales (numerical scales in which intervals have the same interpretation throughout)
4. Ratio scales (Absolute zero) (is the most
informative scale; It is an interval scale with the additional property that its zero position indicates the absence of the quantity being measured; You can think of a ratio scale as the three earlier scales rolled up in one)
What are binary numbers?
The simplest numbers - that is zero or one; often used to to represent whether something is true or false, or present or absent
What are integers?
whole numbers with no fractional or decimal part
What are real numbers?
They have a fractional/decimal part; can be discontinuous or continuous
What is Reliability?
The consistency of measurements across different times or raters.
What is validity?
The extent to which a measurement actually measures what it claims to measure.
What is the Nominal Scale?
Level of measurement where values are categories with no inherent order
What is the Ordinal Scale?
Level of measurement where values have a meaningful order but intervals aren’t equal.
What is the Interval Scale?
Level of measurement with equal intervals but no true zero point.
What is the Ratio Scale?
Level of measurement with equal intervals and a true zero point
What are Descriptive Statistics?
Numbers that summarize and describe data.
What are Inferential Statistics?
Statistical methods used to draw conclusions about a population from sample data.
What is a Parameter?
A numerical value that describes a characteristic of a population.
What is a Statistic?
A numerical value that describes a characteristic of a sample.
