Topic 4 - Surveys and observations

ch6 & stats review (right after ch14)

what are forced choice questions used to measure

e.g. what politician you’re voting for/personality type

what is a poll/survey

a method of posing questions to ppl online, in personal interviews, or written questionnaires 

Likert scale

1 -5 agree/disagree scale 

what is the drawback of open-ended questions

responses must be coded and categorized, a process that is difficult and time consuming

semantic differential format

rating a target object using a numeric scale that is anchored with adjectives

leading questions

the wording leads ppl to a particular response

what kind of question is best in a survey

a simple one!!! 

double-barreled question 

asks two questions in one 

can be convoluted 

negatively worded questions

negative phrasing - causing confusion

thereby reducing construct validity

response set/nondifferentiation 

a shortcut respondents may use to answer items in a long survey, rather than responding to the content of each item 

acquiescence/yea-saying

answering yes or strongly agree to every item in a survey/interview

fence sitting

playing it safe - answering in the middle of the scale for every question in a survey/interview

socially desirable responding/faking good

answering to make oneself look good

faking bad 

giving answers on a survey that make one look worse than one really is 

what are ways to avoid observer effects?

unobtrusive observations 

wait it out 

measure the behaviour’s results 

observational research

The process of watching people or animals and systematically recording how they behave or what they are doing.

observer bias

A bias that occurs when observer expectations influence the interpretation of participant behaviors or the outcome of the study.

observer effect/expectancy effect

A change in behavior of study participants in the direction of observer expectations.

masked design/blind design 

A study design in which the observers are unaware of the experimental conditions to which participants have been assigned.

reactivity

A change in behavior of study participants (such as acting less spontaneously) because they are aware they are being watched.

unobtrusive observation

An observation in a study made indirectly, through physical traces of behavior, or made by someone who is hidden or is posing as a bystander

what are some survey question formats

open-ended

forced choice

Likert scale

semantic differential

what are surveys inefficient in

assessing peoples actual behavior, motivations, or certain memories

what are surveys efficient in

peoples subjective feelings and opinions

descriptive statistics

A set of statistics used to organize and summarize the properties of a set of data

data matrix

A grid presenting collected data.

frequency distribution

A table showing how many of the cases in a batch of data scored each possible value, or range of values, on the variable

frequency histogram

A data visualization technique showing how many of the cases in a batch of data scored each possible value, or range of values, on the variable.

dot plot

A data visualization technique in which every data point for a given variable is represented

central tendency 

A value that the individual scores in a data set tend to center on

mode

A measure of central tendency that is the most common score in a set of data.

bimodal

Having two modes, or most common scores.

multimodal

Having two or more modes, or most common scores.

median

A measure of central tendency that is the value at the middlemost score of a distribution of scores, dividing the frequency distribution into halves

mean

An arithmethic average; a measure of central tendency computed from the sum of all the scores in a set of data, divided by the total number of scores.

variance

A computation that quantifies how spread out the scores of a sample are around their mean; it is the square of the standard deviation.

standard deviation

A computation that captures how far, on average, each score in a data set is from the mean.

box plot

A data visualization technique that depicts a sample’s median, interquartile range (25th and 75th percentiles), and outliers.

outlier

A score that stands out as either much higher or much lower than most of the other scores in a sample.

z score/standardized score

A computation that describes how far an individual score is above or below the mean, in standard deviation units.

cohen's d

A measure of effect size indicating how far apart two group means are, in standard deviation units.

what are the elements of descriptive research

collective data (surveys/observations) 

visualising data (frequencies/graphs/shapes of distributions) 

descriptive statistics (central tendency, variability, single scores, relationships) 

what are the two methods of collecting data

survey methods - asking ppl questions

observational methods - watching what people do

(plus physiological methods)

aggregating data 

the process of collecting and summarizing raw data to create a more informative and usable dataset for analysis and decision-making.

visually or with numbers 

what are the three common things descriptive stats summarize?

the distribution of scores in a variable

individual scores within a distribution

relationships between variables

what are descriptions of how scores are distributed

frequency distributions

shape

central tendency

variability

what is magnitude 

how much? what is the weight of the center of distribution? 

what is variability

how spread?

what is the top of the bar

the mean value of that group

what are the problems with bar graphs 

not intuitive to compare two means 

hides a lot of data that we don’t know 

• doesnt show outlier 

• doesnt show if bimodal 

• doesn’t show if very unequal sample sizes (n) 

what two graphs should you avoid using

pie charts

bar graphs

but bar graph>pie chart

what is under shape?

skey and kurtosis 

what is a normal distribution

‘normal’ describes the type

bell curve

what are floor effects

limitation in the low end of the scale

e.g. household income can’t go less than zero

what are ceiling effects 

limitation in the high end of the scale (can’t go over 100 for example) 

unimodal data 

there is a single most frequent value/peak 

bimodal data

there are two most-frequent values or peaks

rectangular data

there is no peak, all values are about equally frequent

kurtosis

how peaked/flat your data is 

mesokurtic

leptokurtic

platykurtic 

mesokurtic

normal distribution

leptokurtic

very peaked

platykurtic

(plate) very flat 

Σ

sum of everything to the right

x̄ (x bar) or M

mean

N

the number of observations 

what is the equation of x̄

x̄ = ΣX/N

what are deviation scores

X - x̄ 

each data point minus the mean 

central tendency tells us…

where the data is typically located in a distribution

variability tells us…

how consistently the data adheres to the typical value

(spread)

• range 

• variance 

• SD 

range 

total spread of scores in a distribution (max - min)

IQR (inter quartile range)

spread of the middle values

measures of error

how far are values from the mean

standard deviation

the mean deviation score - the middlest deviation score

great for describing spead of scores in a distribution

if you report a mean, always report this too!

variance (SD²)

mean squared deviation score (total variance) 

not great for describing spread (in squared units of measure) 

the FOUNDATION of most inferential stats 

what is the variance equation

what are the steps for calculating variance 

1. calculate a deviation for each score 

2. square each deviation score

3. sum the squared deviation scores 

4. divide the sum of squared deviation scores by N 

standard deviation equation

	=	population standard deviation
	=	the size of the population
	=	each value from the population
	=	the population mean