in this research methods and psychology video we're going to cover research aims and hypotheses
and what the difference is between them i'm also going to explain the different types of hypotheses
and when we would use them psycboost.com over 170 videos to help you with your qualification
and patreon supporters can access bonus resources tutorial videos and the discord channel you might
have a general area of psychology that you want to investigate say i want to investigate how
memory can be improved but to give an aim we need to narrow this down to a clear statement
that outlines what you as a researcher intend to investigate the aim can include why you want
to investigate it so stating the purpose for the study purposes could be because previous research
raised interesting questions or maybe you're directly replicating someone else's work
we can phrase an aim as a question or a statement so an example aim could be the aim of this
research is to find out if colour can influence recall we can even add due to previous research
showing exposure to green plants increase recall so with an aim we know what we're studying and
perhaps why but not how we need to be more precise if we're going to conduct a study and importantly
communicate to other researchers exactly what we're doing so after our aim we're going to
make or formulate a hypothesis a hypothesis is a precise statement that importantly can be tested
this means i need to state how the parts of the study interact so in an experiment
i would state in my hypothesis exactly what the levels of independent variables are and what the
dependent variable is in this example let's say my hypothesis is there is a difference in the
number of words recalled by participants recalling in blue light compared to participants recalling
in green line i would also need to be careful to operationalize my variables meaning i state them
in a way which shows how they're measured so instead of recall the number of words recalled
now an important point about hypotheses they're not predictions they're statements of fact now of
course we reject or accept a hypothesis depending on the evidence we collect so what's going on well
we actually have two hypotheses as good scientists we begin with the principle that there is
no difference between the conditions or no relationship between the variables
this is called a null hypothesis or hate zero of course scientists want to be able to show
that there is a relationship between variables but similar to a courtroom where they say innocent or
proven guilty we accept the null hypothesis unless we collect evidence powerful enough to reject it
are other hypothesis you might be more familiar with it's called the alternate hypothesis or h1
and this just means it's the alternative to the null and it suggests that there is a difference
between the conditions it's also known as the research hypothesis in hypothesis testing we start
with both hypotheses collect our data and then use statistical tests on the data this then provides
evidence and if the evidence is strong enough we can reject the null hypothesis and accept
the alternate hypothesis i'm going to go into how we decide on the strength of evidence more
in the probability and inferential stats videos so we know the difference between the null and
the alternate but the alternate can be written in two ways we can give a directional hypothesis
also known as a one-tailed or a non-directional hypothesis also known as a two-tailed hypothesis
a non-directional hypothesis states that there is a difference but not which way the direction will
go a directional hypothesis states that there is a difference and how the results will go so let's
look at my example again there is a difference in the number of words recalls by participants
recalling in green light compared to participants recalling in blue light there is an increase in
number of words recalled by participants recalling in green light compared to participants recalling
in blue line so by changing the word difference to increase the second hypothesis suggest that not
only will there be a difference but that direction that difference will go the researcher will use a
directional hypothesis if this previous research that indicates the direction the results will go
so imagine if there was significant research that being surrounded by green plants improves recall
i might use a directional hypothesis as i have reason to assume the direction my results will go
bonus fact i haven't done many bonus facts in the research methods videos
but this one's important and it's about the word proof we shouldn't actually use the
word proven science proven means true totally true 100 absolutely no chance of being wrong
well that just doesn't work in science any theory has to be open to more evidence coming along and
showing it isn't true that's called falsifiability and if a theory isn't falsifiable it isn't science
we have the null and the alternate hypothesis and we collect evidence so we can reject one and
accept the other based on that evidence well how strong that evidence is is based on probability
in psychology we accept the alternate hypothesis when the probability that the results are a fluke
is one in 20 or less that means that even when we accept an alternate hypothesis the
likelihood that we just got the results by random chance of five percent or less never zero percent
so accepting an alternate hypothesis because the evidence is strong enough is not proving a theory
it's saying the evidence is not perfect but strong enough for us to accept it for now so my advice in
your essays is don't use the word prove anymore but do say that the evidence supports the theory
it's going to make you sound much more scientific but you'll now hear and read people using the word
prove and proven incorrectly from now on and i imagine it'll annoy you as much as it does me
so that was aims and hypotheses i have six tutorial videos covering the 17 18 and 19 a.s
and a-level research method sections and these videos have worked examples to every question
and are full of exam tips patrons at the neural level and above can access these as well as many
many more hours of exam tutorial videos as well as over 100 printable resources from
across the a level over on siteboost.com i do want to thank all the students and teachers
who have supported psycboost over on patreon during the development of the research methods
unit it's their support that allows me to teach part-time so i can make psycboost on youtube for
everyone so thanks to them and i'll see you in the next research methods video sampling
you