statistical tests

Question 1

what is the point of a statistical test?

Answer 1

CANNOT BR USED TO PROVE ANYTHING

allows us to prove VALIDITY of conclusions

Question 2

chi squared test
(comes up a lot)

Answer 2

use for FREQUENCY data

CANNOT USE JUST ONE CATEGORY

eg. no. of white and purple flowers in pop of pea plants

if OBSERVED freq fits freq you EXPECTED

Question 3

(how do we calc expected freq?)

Answer 3

• might expect data freq to match a RATIO of phenotypes in genetic cross
• might expect homogeneous distribution of individ. in env

Question 4

what can spearman’s rank tell you

Answer 4

whether there is statistically significant CORRELATION between 2 measurements from same sample

when you have 5-30 pairs of data

correlation is either +ve or -ve

Question 5

evaluate

Answer 5

• review info then bring together to form a CONCLUSION
• draw on evidence including strengths, weaknesses, alternative actions , relevant data -> can include maths explanations

Question 6

comment on

Answer 6

use data to form a judgement

Question 7

criticise

Answer 7

inspect data and consider elements

look at merits / faults on info and support judgements made by giving evidence

Question 8

deduce

Answer 8

reach conclusion from info

Question 9

describe

Answer 9

give an account of smt but DO NOT NEED TO INCLUDE JUSTIFICATION

Question 10

discuss

Answer 10

• identify issue being assessed in q
• explore all aspects of issue
• investigate issue by reasoning or argument