introductory/ key words and explinations Flashcards
Sampling bias- volunteering
Ora 1965- thinks experiments using volunteer samples may contain sample bias simply because they are volunteers.
cowles and davies 1987- found females and extroverts to be more likely to volunteer- this highlights the possible issue of sample bias- type of person who volunteers.
Advantages and disadvantages on online sampling
page 56 of first required book
advanatges + disadvantages of repeated/independent designs
page 86 of first required book.
descriptive stats
organising and summarising data using graphs and numbers.
measures of central tendency
where do we report them?
mean, median, mode
results normally start with these-usually a table
measures of variability
how spread out are your scores
range, variance, standard deviation.
coolican (2019)-range= top value from bottom and add 1
what is a bimodal distribution?
and multimodal
2 distinct peaks
more than 2 distinct peaks
kurtosis?
peak or flatness of data
leptokurtic- high kurtosis=very peaked distribution and spread of data is shallow- in spss its positive values
platykurtic- flatter distribution= lower kurtosis- in spss its negative value
mesokurtic- between the 2 extremes above- in spss=0
this is a way of describing data.
what is a floor effect?
what is a ceiling effect?
when a measure produces most values near the top of a scale e.g. a very easy test
when a measure produces most values near the bottom of your scale e.g. a very hard test
standard normal distribution
normally shaped distribution mean is 0 standard deviation is 1 split into percentages i have notes on this in my stats book
sampling error
the difference between the sample statistic and the population statistic
what is a bimodal distribution?
Has 2 modes
what is a conditional probability
the probability of something happening if another event or set of conditions has also happened.
