Lecture 2

Question 1

What is a discovery science

Answer 1

observe→describe→analyze data→conclusion

Ex. sun rises from the east, organisms are made of cells

Question 2

what is a Hypothesis–based science

Answer 2

hypothesis→test predictions→analyze data→conclusion
Try to explain the observations of discovery science. Support or not the hypothesis.
If it supports, experiment repeated x times by you and different labs and may become a theory
If not supported, reject your hypothesis and modify it and redo

Question 3

what is a valid Hypothesis

Answer 3

Proposed explanation for an observation that is testable
Should generate predictions
Data will either support it or not
Never say the hypothesis is right// proven true (we can’t say with 100% certainty)

Null hypothesis: predict that there is no difference
Alternative hypothesis: there will be an effect

Question 4

diff between null and alternative hypothesis

Answer 4

Null hypothesis: predict that there is no difference

Alternative hypothesis: there will be an effect

Question 5

diff between one tailed and two tailed hypothesis

Answer 5

→ one tailed: directional hypothesis (you specify the effect, is it positive or negative)
→ two tailed: non-directional hypothesis (you just say there is an effect/ difference, not specifying if positive or negative)

Question 6

what are Factors to consider when designing an experiment

Answer 6

Large sample size
Identify dependent and independent variables
Identify control variables
What is the control group
Include placebo to evaluate the placebo effect

Question 7

diff between biological and technical replicates?

Answer 7

→biological replicates: parallel measurements of biologically distinct samples that capture random biological variation
→ technical replicates: repeated measurements of the same sample

Question 8

diff between dependent and independent variables

Answer 8

→ independent: you control

→ dependent: you measure

Question 9

what are control variables

Answer 9

→ variables that could influence experimental results and must be held constant during the experiment

Question 10

diff between control and test group

Answer 10

control group almost identical to the test group, differs only the independent variable studied

Question 11

… studies are used to reduce the placebo effect

Answer 11

double-blind

Question 12

what are some cause and effect tests

Answer 12

t-test, chi-square test

Question 13

the p value should be… ? and why?

Answer 13

We want the p value to be less than 0.05, if not, the results are not significantly different

Question 14

diff between paired and unpaired t test

Answer 14

Unpaired: independent groups
Paired: dependent (before and after)

Question 15

what do we say instead of hypothesis proven

Answer 15

the hypothesis was supported or not supported.

Question 16

rule of thumb: a study should have at least ___ people

Answer 16

100

Question 17

what is a correlation

Answer 17

regression analysis, looking for a relationship

When 2 or more events occur at about the same time and might be associated with each other

Correlation DOES NOT EQUAL cause & effect