Class Notes (839,146)
Canada (511,218)
Joe Kim (15)
Lecture 2

Lecture 2 - September 13 - LIFESCI 2A03

2 Pages

Life Sciences
Course Code
Joe Kim

This preview shows 80% of the first page. Sign up to view the full 2 pages of the document.
LIFESCI 2A03 Lecture 2 September 13, 2013 Hypothesis  Hypothesis – a proposal or explanation  A scientific hypothesis – a proposal that makes a prediction; application of the scientific method allows one to test the hypothesis  Tentative explanations that account for observations  Hypotheses inevitably lead to predictions about the result of intervention  Predictions can be verified or refuted by analyzing the data  The formulation and testing of hypotheses is the basis of any scientific or rational inquiry Logic  Inductive Logic (induction) – inductive generalizations summarize a set of observations and serve to provide a prediction about unseen events; singularity to generality o Eg/ This ice is cold; therefore all ice is cold  Deductive Logic (deduction) – going beyond the formulation of hypotheses formed by induction to test whether they are correct involves the use of deductive logic; have generality, make hypothesis about singularity o Eg/ if all green apples are sour, then this green apple will be sour o A hypothesis is followed by a prediction:  If – (generalization)  Then – (specific instance you are testing)  This is called a deductive syllogism  The fact that this deductive syllogism lead to predictions means that hypotheses can be tested Logic, predictions and testing hypotheses  Truth Table o If you obtain a false prediction, the hypothesis must also be false – if the result is inconsistent with the prediction, you must reject the hypothesis o If you obtain a true prediction, the hypothesis may be true or false – true predictions do not constitute proof for the truth of the hypothesis, you fail to reject the hypothesis o Never say hypothesis is TRUE  hypothesis is good predictor, consistent with data, do not reject hypothesis o True prediction doesn’t tell much about truth of hypothesis; consistent or inconsistent with data  Null Hypothesis – statistical term (not simply the opposite of your hypothesis); simple way of saying that there is no (significant) difference between two sets of results o Eg/ A difference in observations between a control group and an experimental group in which you have introduced an intervention  Eg/ Regeneration; control = newt; experimental = add chemical to speed rate of regeneration  Null Hypothesis: there is no significance between chemical and rate of regeneration (two sets of results) o Eg/ Observations of two groups in two different conditions  Two populations of birds  Null Hypothesis: there is no significant difference between the two groups o Eg/ A set of predicted results and the observed results Case Study 1; Brain Freeze  If one thing is going to ruin a bowl of Ben and Jerry’s more than reading the ingredients label, its getting that searing ice cream headache. It’s almost enough to put you off having a second bowl. Almost enough, but not quite.  What is a brain freeze or ice cream headache?  Ice cream evoked headaches (ICE-H) study: randomized trial of accelerated versus cautious ice cream eating regimen  Kaczorowski, M and J. Kaczorowski. 2002. BMJ. 325(7378):1445-6.  Compared the effect of two ice cream eating regiments on the incidence of ice cream induced headaches  Hypothesis – If you eat ice cream quickly, there is a
More Less
Unlock Document

Only 80% of the first page are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.