1.1 The Nature of Science

Science

the study of the natural world

Key Features

1. testable

2. repeatable

3. fallible

BPQ- what does science say about demons?

nothing-they are supernatural–outside the natural world!

Science Dirty Words

words that suggest infallibility (prove, truth, know, fact)

alt. words: supports, suggests, corroborates

Steps of Scientific Method

1. make observations/form questions

2. make hypotheses

3. run experiment to test hypotheses

4. analyze data results

5. make conclusion/theory (hypothesis tested over and over)

Laws

• describes repeatable observations, but don’t explain them

  • are NOT part of the scientific method

Hypotheses

possible answer to question

requirements:

1. testable solution

2. written like an answer

   1. not written like an opinion (“I think”)

write enough to cover ALL possible outcomes!

Hypothesis forms

1. H_0 & H_A

   • Null Hypothesis - no change/effect

   • Alternative Hypothesis - there is a change/effect

2. H_1, H_2, H_3

Independent variable

IV

variable you change

Dependent variable

DV

variable changes in response to independent variable

Control Group

a group for comparison that creates conditions where only the independent variable is changed/can be observed

Control variables

variables you attempt to keep constant b/w your control & experimental groups

placebos

prevent behavior from affecting the experiment; helps keep conditions same b/w experimental & control groups

Hypothesis template

H_0 – The IV has no effect on DV

H_A – The IV has an effect on DV

Goal of hypothesis testing

falsify all but one hypothesis

1. H_0 & H_A

   • falsify the null hyp. – failing to falsify H_0 does NOT mean H_0 is supported

2. H_1, H_2, H_3

   • falsify 2/3 hypotheses

Negative Control Group

• shows what failure looks like

  • almost always present

Positive Control Group

• determines what success looks like

• checks whether experiment procedure worked

• not always necessary

Statistics

often necessary to determine whether 2 groups are objectively different

1. Error bars

2. confidence intervals

3. chi square (x²)

Error bars

overlap = not stat. diff.

no overlap = stat. diff.

Confidence Intervals

ex. avg. height of 1st pd: 5’8”±2”

Ontology

• the nature of being

• “what is something”

• what is a helium atom - defined

  • who are you? - diagnosed (checks boxes)

Epistemology

• study of knowledge

• “how do you know when you know smt?”

Parsimony & Occam’s Razor

Parsimony

solution with the least # of assumptions is most probable answer

• form of Occam’s razor

• Most impt. epistemologic concept in science

Occam’s Razor

simplest solution is the most probable answer

Importance of parsimony

any falsified hypothesis can be rescued by an ad hoc hypothesis

Ad Hoc Hypothesis

a hypothesis added onto a previous hypothesis to rescue it via parsimony

BPQ: why is the flat earth “theory” not a scientific theory?

• uses inductive reasoning

• makes too many assumptions (not parsimonous)

Induction

look at evidence to support a hypothesis

Deduction

look at evidence to reject a hypothesis

which is better: induction or deduction?

deduction