ladies and gentlemen it's time for another edition of psychology
and today we're doing research methods
so please welcome new host its Will Carne
and Sarah Coleman
yes that's right hello I am Will Carne
and I'm Sarah Coleman and welcome to some research methods a2
psychology Brea be a and a
if you've missed the as- research method you will need to know pretty much a lead
to be able to cope with this video so if you wanna recap stops
however that video you could probably click the screen now if I'm so clever
if not then you come and bats that's makes sense
feel putting on the description bright free very quick recaps
firstly the measures of central tendency Sarah he's measures where the middle is
and hunted they all began with an the mean and
the mod and median you should know this from last year
measure of dispersion and are measures the house but out the dangerous the 32
the range and standard deviation you need to know how to work at the range
the highest number take away the lowest number
an hour but you do need to know that the standard deviation is beings
that the spread or the data around the main
that makes sense and again you don't know this nasty is the recap: service
what it means
crops and I last year grass but shots cuts across histograms an option on slut
big the body ons
these again another leave it is but we were just reminding you
that you get lows in March from trivial things like titles
axes titles and labels and sometimes even eight key
it's hard to describe the graphs as there are so many ways of doing these
classy you each have your own way
so honest and helpful vision yes
levels measurements how or what and why which I really sad for the different
types no minno
or to know into I'm ratio you need to know all full as you may be asked what
each one is
number noted data is best described as critically data
simply being the number things neat sketch going ordinal data is data let me
place in to rank order from highest to lowest or vice versa
it is possible to say that one value is higher than the other but no more
interval and ratio data consisted data to measure it with pics and
equal distances between all-points on the scale the difference is the value of
0
within 20 days that they can be negative numbers 0 doesn't mark the start at the
scale
like temperature for example ratio desert though has a absolute value of 0
for example
meters in seconds where there are provides the baseline you need to a diff
is chain
ordered these the case although you only need to know if it's no no I at least
order of a test he may be us to define each one onto
differential statistics those tests you just spoke about 07
ho speaking at yes and here's the way productions which test guide
yet 30 you need to ask whether it's no minno
this time its chi-square if it isn't nominal
it must be at least ordinal and then you ask yourself it is a correlation
if yes then use Spearman's rank gave its isn't quite nation then you ask yourself
whether it independent group design
yes then it's a mann-whitney if it isn't it must be related which means it is
either matched pairs or repeated group design
then it will be Wilcoxson when you explain what fact 58
it's important you mention everything for example if the data is no minno
you know it's a chi-squared but you need you still need to say whether it's a
coronation
it's not what society's except extension this is cool justifying your choice
on Tuesday never consider level or
p it is used to judge what the results are significant meaning that is is
unlikely to have occurred by chance
level is often shown like this meaning the probability
are the results being to chance is less than or equal to not point not
by of 5 percent observed and critical money
to see if the results are significant you will need to carry out one of the
tests we went over earlier
luckily he won't have to carry out the actual test but you will probably have
to do the last part involved with the tables
you should it be given the observed calculated value which the unique value
which pretty much sums up your results on what you've got
you need to then know the significance level whether you have process
is one bushy tailed if you aren't a given a significance level 10
as this stand it is not quite not fun then you need
a notice a data which varies by test for mann-whitney
you need and and a the number to spence or
day to results in each condition the law will cost and you need and that the
highest to run
this payment thank you again need and for number fifty states and folk I
squared
you need to find the degree of freedom found by multiplying the number
rows in the table -1 by the number of columns -1
using this data you can use it able to get a critical funny
and then you just use the centers at the bottom of the table or in your exam
question paper
which will tell you when the result significant using your debit in critical
values
if the results are significant and a check to null hypothesis
and accepts the alternative hypothesis unfortunately
deck and the everest made when conduct conducting statistics
the need to know about the tud the two types one
and to took one is when you get a false positive
and accuse when you get a false negative so tight one is when you project the
null hypothesis when really the results on significant
and type 2 is when the null hypothesis is accepted and the alternative
hypothesis
is checked onto reliability
yet paying now with all these new research method you need to know a
little bit more about reliability and validity
in particular its meaning in the three study types experimental
observational and self-report so the experiment to the reliability is the
ability to repeat study and obtain the same result
with all the conditions the same I E to people
with observational the reluctance is measured by interobserver reliability
the extent to which to observe is observing the same thing at the same
results
as can be improved by train which might involve watching a video of an example
event
and the observers discussing to ensure they're looking for the same quality
several studies reliability Camille it had as in 10 extent
internal is whether it's consistent within itself so whether the questions
in measuring the same thing
an Excel be whether it's consistent are many different occasions
so if repeated with everything the same the same results would be gay
that took three takes it can be measured by the split I'll
at the door by the test-retest method the Sprint Cup method compared to
persons results on the two pops a protest
and the test-retest meant that give the participants at the test the week
also later and see that they gain the same results this applies to interviews
as well
his cute kitty onto the lead today which is split into internal
and external internal being whether they test what they intended to test
and Xterra being with the results can be generalized other situations and people
again you need to know the scenarios for checking and improving each study
day for experimental real estate the in 10 a village tea is affected by
the extreme step does maybe you have tested them rather than the DV you ain't
tests for external it see it is the relevance and applicability to other
situations
for observational is a it lacks in general it see if the behavior checklist
is flawed
did you observe the bus so any reason that you haven't tested what you
intended
for self reports studies Phyllis T in 10 ability can be tested
in two ways faithful in st. whether it looks at
looks as if its measuring but the resurgent ended measure
and concurrent validity where you compare the results of another study you
know the house by the results on the river
if the results a similar to yourselves you can conclude that you're not a valid
which is kinda cheating
year external policy can be effected by some patients tease
picking selections at the population meaning it might not generalized
everyone
the teachers tend to be specific to the study these are very general points and
just generally a tan II how to
check the glitzy and reliability and how to improve it
so many are you can do that in your own time
pay you for watching research methods part hey which has been analyzing
studies
join us for part be planning studies next time goodbye I'm will come
and i'm sarah common man happy psychology a nap setback catch phrase