Research Methods (yr13) Flashcards
What is the difference between a null hypothesis and a hypothesis?
Hypothesis says that there is a difference or relationship between two things.
Null hypothesis says there is no difference or relationship between two things. Any difference seen is down to chance or another factor
What are statistical tests used for?
To asses the probability of results occurring due to chance. This increases the scientific credibility of the research.
It allows us to decide which hypothesis to accept or reject
What is the accepted level of probability?
All studies employ a significance level, the accepted level of probability is 0.05% or p </= 0.05
This strikes a balance between type 1 & 2 errors.
Why would a more stringent level of significance be used (0.01%) ?
This may be used if there is a human cost such as a drug trial or if the study is a one off and cannot be repeated in the future.
What is a type one error?
A type one error is when an experimental hypothesis is wrongly accepted and null hypothesis wrongly rejected due to the significance level being too lenient.
Known also as a false positive.
What is a type two error
A type two error is when an experimental hypothesis is wrongly rejected and a null hypothesis is wrongly accepted.
Known as a false negative.
