Ch.2: research methods Flashcards
empiricism
The belief that accurate knowledge can be acquired through observation
theories
hypothetical explanations of natural phenomena; ideas about how something works
hypothesis
a falsifiable prediction based on a theory
what are the methods (2) used to study human behaviour?
- methods of observation (determine what people do)
2. methods of explanation (why people do what they do)
operational defintions
a description of a property/variable in measurable terms
ie: for example, we might operationally define happiness as “a person’s self-assessment” or “the amount of dopamine in a person’s brain” or “the number of times a person smiles in an hour.”
construct validity
the extent to which one adequately characterizes the property/variable; how well a study conceptualizes it variables
ie: measuring smiles per hour to measure emotions per day over measuring their IQ
power
the ability to detect the presence of differences or changes in the magnitude of a property
empirical method
set of rules and techniques for observation
the scientific method
a procedure for using empirical evidence to establish facts.
naturalistic observation
gathering data by observing behaviour in an ordinary setting, without researcher interference
what are a case study/method and some of its disadvantages
- the deep study of an individual or small group in hopes of revealing universal principles
- research usually on unusual phenomena
- DESCRIBES behaviour (experimentation explains it) what cant always be studied in a lab
disadvantage: large time commitment, the small number group is NOT representative of the population as a whole (experimentation can be used to apply what learned to the larger population(
correlational research
requires at least two variables to be measured so that one variable can be used to predict the other
- NO variable manipulation by researcher
disadvantages of experimentation
some variables cant be manipulated without violating ethical standards: - informed consent safety - privacy of data benefit to society - a benefit to participants
demand characteristics
settings that cause subjects to behave as they think someone else (eg. experimenter) wants or expects
how to avoid demand characteristics?
- naturalistic observation
- if you cant do naturalistic observation:
privacy and control
- gathering info privately or anonymously
- measuring behaviour that people are unable or unlikely to control (such as dilation of pupils to tell whether or not you’re lying)
unawareness
- make sure ppl are unaware of the true purpose of the observation
how can you avoid observer/experimenter bias
double-blind design: neither the researcher not the participant knows how the participants are expected to behave
- avoids the placebo effect
normal distribution
where the most measurements of a frequency distribution are concentrated in the middle
mean = median =mode
what are the descriptive stats of central tendency?
mode: the value of the most frequently observed measurement.
mean: the avg value of all the measurements.
median: the value in the middle
descriptive stats:
s calculated from a distribution of scores, indicating the central tendency (avg) and the variability; brief summary statements aBOUT ESSENTIAL INFORMATION FROM A frequency DISTRIBUTION
- indicated whether or not experimental treatment changed performance
third-variable (confounding variable)?
correlation between two variables cannot be taken as evidence of a causal relationship between them because a third variable might be causing them both
the third-variable (confounding variable) problem?
correlation between two variables cannot be taken as evidence of a causal relationship between them because a third variable might be causing them both
***why correlation DOES NOT = causation
what’s a solution to the third-variable problem?
- experimentation: eliminating or controlling other possible causes, thus creating a a set of conditions that differ in ONLY ONE WAY. Experimentation finds causal relationships
- via manipulation: a technique for determining the causal power of a variable by actively changing its value - randomization
a good detector has ____ and _____
power and reliability
If a person smiles a bit more often on Tuesday than on Wednesday, a powerful smile-detector will detect different amounts of smiling on those two days. If a person smiles exactly as much on Wednesday as she did on Tuesday, then a reliable smile-detector will detect identical amounts of smiling on those two days. A good detector detects differences or changes in the magnitude of a property when they do exist (power), but not when they don’t (reliability).
negatively skewed data leans to the….
right
positively skewed data leans to the
left
standard deviation
how each of the measurements in a frequency distribution differs from the mean; involves finding the distance between each individual score and the mean, and then computing the average of these distances.
- indicate how many exceptions there are.
- when the standard deviation gets larger = the more the two groups overlap and the smaller (weaker) the effect size and vice versa (smaller SD = less overlap = stronger effect size)
if the distribution has extreme scores that pull the mean in their direction, researchers prefer to use the:
median
What’s a limitation of naturalistic observation?
** describes behaviours but cannot explain why they occur which is why we need experimentation
frequency distribution
a graphic representation showing the numner of times in which the measurement of a property takes on each of its possible values
sample
a partial collection of people or animals or things drawn from a population (n); representative of the population
population
a complete collection of people (N)
correlation
when variations in the values of one variable are synchronized with variations in the value of the other
what is direction (r) in a correlation?
the direction of the correlation = positive or negative;
- positive = “more is more”; ppl have a lot of one variable also have a lot of the other; r=1
ie: more health is associsated with more wealth - negative = “more is less”; r= -1
ie: more health is associated with less poverty
*the sign associated wit r
variability
the extent to which the measurements differ from each other (range, standard deviation, etc)