Midterm Flashcards
Psychophysics
the study of how changes in physical stimuli are translated into psychological experience.
psycho=internal impression
physics= external world
Central Tendency
descriptive statistics indicating the center of the distribution.
mean=ΣX/n
median= once scores on in order the middle # is the median.
mode= most frequent # in set
mean geometric= x1x2x3…=
Parametric Statistical
tests make assumptions about the underlying population parameters of the samples on which the test were performed.
Operational Definitions
describe the procedures used to produce a concept and allow us to communicate successfully about the concepts we are studying.
Method of Adjustment
start below the threshold to find just what you can hear. Down to up and back down. Just hearing vs just don’t
Not very accurate
Method of Limits
in order to measure a subjects perception of a stimuli. A stimulus is presented in an ascending/ descending pattern of ADDA. Threshold is found when individual switches from “yes” to “no” or “no” to “yes”.
Method of constant
Most precise. Present each of the stimuli in random order
Staircase Method
concentrated responses around the threshold. For the first trial it is similar to the method of limits. Once the estimate of threshold is found, the stimuli are never presented far from the estimate.
Difference Threshold
the minimum amount of stimulus change required to produce a sensation difference.
are based on relative judgements, in which a constant unchanging comparison stimulus judged relative to a series of changing stimuli.
Ex: lifting a pair of weights- one weight always remains the same- observer judges if new weight is “heavier, lighter, or equal” to the standard weight.
Error Bars
show the limits of where the mean will be if the experiment is ran again.
If the error bars overlap, it is unlikely the experiment is significant.
Fechner
the physical world is separate from psychological world (stimulus –> response)
Semi-interquartile Range
Used when the distribution is not normal. Measures the variability by dividing a data set into quantiles. Q3-Q1
Central Limit Therum
as “n” goes up the distribution gets narrow and normal/
Weber’s Law
is important because it tells us what we need to know about the environment.
In very weak and very strong conditions Weber’s law does not work.
Ratio’s always stay the same.
DL/S=K
DL=Difference Limen
S=Standard stimulus
K=Constancy
Scientific Method
fixed belief on the base of experiences.
- State a problem
- Formulate a hypothesis
- Test an experiment
- Outcome
3 Goals of Research
Description ———-> Observational Research
Prediction ————> Correlational Research
Control Inter-causality —-> Experimental Research
(Manipulating the variables)
Types of Measurements
Nominal-Qualitative. measures the difference ex: male female, Zip codes, undergrad programs. Categorical
Ordinal- measures differences and magnitudes. Ranks/ In order
Interval- properties of difference, magnitude, and equal intervals
Ratio- all four properties difference, magnitude, equal interval and meaningful zero.
Properties of measurement scales
Difference- ex temps are colder/ warmer or ex male and female
Magnitude- scale can show that one attribute is grater than or less than
Equal Interval- ex: a 1lb difference between 2 weights is the same when considering 1 lb vs 2 lbs or 70 lbs vs 71 lbs
True zero- a zero on the scale that indicates nothing of the attribute being measure exists.
Just-noticeable difference
is the internal sensation of change when it is just noticeable. Ex: a room getting gradually lighter the moment you notice the change of the rooms light
Interval of uncertainty
the difference between the higher and lower threshold in the calculation of the difference threshold.
Point of subjective Equality
is the mean of the upper and lower threshold
Error of Expectation
expecting to hear change so the response is “I’m expecting to hear… so yes I hear it”
Error of Habituation
When you make a response of hearing that is beyond what can be heard
Counterbalancing
is used to avoid the introduction of confounding variables. Controls the order effects
3 Standard Deviations
SD of a sample = SQRT of Σ(M-X)2 / N-1
SD of a population = SQRT of Σ(M-X)2 / N
SEM= Est SD of population/ SQRT N
Absolute Mean Deviation
AD= Σ | x - µ | / N
Absolute Limen (threshold)
is the smallest level of energy required by an external stimulus to be detectable by the human senses, including vision, hearing, taste, smell and touch.
Confounding
when more than one independent variable is simultaneously varied so that it is unsure which variable is responsible for the outcome.
For example, if you are researching whether lack of exercise leads to weight gain, lack of exercise is your independent variable and weight gain is your dependent variable. Confounding variables are any other variable that also has an effect on your dependent variable.
Interaction
event that occurs when the effects of one independent variable are not identical across different levels of other independent variables
Deduction
reasoning proceeds from a general theory to particular data
Induction
reasoning proceeds from particular data to a general theory.
