Outline

• Go over the reading: summarize reactions

• Intro talk: the scientific method – Concepts and frameworks we’ll use

• Examples from a few readings

• An overview of today’s lab

• Prep work and logistics for the lab

• Assignments, schedule changes, etc

ScienceA framework for solving problems

and making sense of the world around you

New College

• Problem-based seminars

• Science occupies an embattled, problematic place in our world

• Conflicts and controversy over the politics of science are frequent and require scientific literacy

• Hands on experience with the scientific method

Points to take away from the reading in Angier: intro

• Science: it’s not just for little kids

• Misunderstood and embattled, but useful– No $, no fame, yet the engine of society

• Thinking scientifically is underrated

Points to take away from the reading in Angier: Ch2

• Science: not just a body of facts

• Universality of the scientific method

• Scientists believe there is an objective reality that can be unmasked through tools of science

• Wonder can be cultivated

• Quantitative thinking can be helpful

• Facts, not truth, and science is not opinion

Points to take away from the reading in Angier: Ch2

• Bias and bad data are our enemy– Experimental design and controls– Blinding studies

• Approaching the same problem via multiple routes is often the best way and gives the findings credibility

• Science is based on defending your data and conclusions in a peer group of others

Points to take away from the reading in Angier: Ch2

• Scientists think in grey tones and often arguments are not well translated to the popular media

• Scientists are fixated on the unknown and debate: they are attacked on these grounds by non-scientists who fail to understand what science is all about

• We are often superstitious creatures who believe things with no evidence; most scientists yield only to scientific arguments

SO

What does scientific literacy mean?• Being able to sort out what constitutes science and what does

not– Good science versus pseudoscience or bad science

• Comfort with common terms and concepts involved in the scientific method– Fluency in scientific language (download vocabulary)

• The ability to explicitly design, conduct, and communicate a science experiment

• Attaining an understanding and appreciation of uncertainty and conflicting viewpoints– Non-dualistic thinking– Understanding of science as a process

• Scientific thinking is applicable to everything

Science as process• The scientific method is a way of approaching

the world around us• Not mystical or specialist• Usually more questions arise than are

answered – more hypotheses are generated• Inherently iterative• You have to expect that you will be proved

wrong. We are all blind men describing elephants.

Hypotheses

• Usually defined as “an educated guess”– What is that?– A question that arises from observing the world around us

• Often includes inherent bias– Sometimes no one asks the right questions or only asks

questions to which they already think they have the answer

• Can be the product of inductive or deductive reasoning– Inductive reasoning is generalizing– Deductive reasoning is

• Must be falsifiable (Karl Popper) and testable – Useful in determining what hypotheses are scientific (or are

political, pseudoscientific, etc)

Scientific method

• Approximately 11 Steps

• Process is repeated many times

• Can NEVER prove a hypothesis– Can only reject many, leaving one as best

supported by the data– “Scientific Proof” is a common fallacy– Associations don’t prove causation– FACTS not TRUTH

Scientific method - Steps 1-5

• Observe or suspect pattern

• Posit significance of observed difference

• Create question to explain pattern

• Create testable hypotheses

• Design experiment

• Collect data (descriptive stage) • Analyze data, primarily using statistics • Evaluate hypotheses, accept or reject them• Make conclusions based on data • Note problems in current work• Predict future directions for research

• The process is the structure for write-ups

Scientific method - Steps 6-11

Parts of a scientific report

• Title • [Abstract - an overall summary]

• Introduction - background, question, Has

• Methods - what we did• Results - what we found, graphs, summarized data• Discussion - interpretations, predictions • References - who we cited

• Document on course website!

Scientific Communication • Written report

– Traditional

• Oral presentation – Commonly used for preliminary presentation of work

to get feedback before writing it up

• Poster – Visual summary of work - used at conferences

• Web page – Can use a written report & make it interactive

Experiments

• Independent variable: one thing that changed (measured)

• Dependent variable: outcome (measured)– This language comes from math: y=mx+b

• Usually experiments must be repeatable– Some are not repeatable or even ethically

repeatable

• Always use controls – snake and tadpoles• Ethics and experimental design

Key concept: reasoning

• Inductive reasoning: – Generalizing: This floor is hard, all floors must be

hard

• Deductive reasoning:– (Coming to a conclusion based on premises: all

birds have feathers, an ostrich is a bird, so all ostriches have feathers)

• Key in hypothesis generation and in drawing conclusions from work

• Often extensions are not valid

Key concept: errors in analysis• Type 1 error: "false positive": the error of

rejecting a null hypothesis when it is actually true; observing a difference when in truth there is none.

• Type 2 error: "false negative": the error of accepting a null hypothesis when the alternative hypothesis is the true state of nature. In other words, this is the error of failing to observe a difference when in truth there is one.

Key concept: Occam’s razor

• AKA Law of Parsimony– The simplest explanation tends to be the best

• Often also the least entertaining• Means that we’re better off not using our imagination too

much when trying to explain natural phenomena

• Simpler theories are often easier to test, so science is biased in favor of them (K.P)

• Einstein: OR doesn’t mean simplification is best. Things should be made as simple as possible, but no simpler

• Key Concept: the precautionary principle• The precautionary principle states that when

science is extended and there are risks of irreversible risks to human health or the environment, the burden of proof is on the doer.

• Species extinction, Global warming, GMOs, Public health, Persistent or acute pollution (endocrine disruptors, asbestos), Food safety (CJD), Artificial life, new designer molecules, etc

Key concept: Non-Western science

• Sometimes pseudoscience, often not

• Ethnobotany, ethnopharmacology, ethno-etc.

• May be linked with superstition or religion

• Often provides real insight that can be co-opted by university-trained scientists from rich countries– Inoculation/vaccination– Geography

• Under the radar

In-class readings

In-class readings

• Identify hypotheses, explain experimental methods and analyses, and discuss outcomes

• Were controls used? How?

• How are these experiments similar/different?

• How did this study contribute to the creation of new knowledge?

Agriculture lab

• Woman’s oldest science

• “Trial and error” and logic are always used– Observing what works and what doesn’t– Often leads to spurious conclusions

• Like hanging bags of water on the wall• Mangoes and sugar

• We’ll be using our basic knowledge of the scientific method to explore the effect of soil composition on crop development

Background

• NPK• Various materials add these macro-

nutrients– We have a few on hand here– Blood meal, bone meal, greensand– Composted cow doo doo (scientific term)

• We want to know whether adding these things to the soil will achieve a measurable increase in plant growth

Experimental design

• Three plots, all with different soil types

• Unimproved soil

• Soil with composted manure

• Soil with composted manure and NPK additives

• Outcome of interest: plant development

Hypothesis

• We want to know____________________

Materials and methods

• Tools we need

• How do we intend to go about answering this question?– Data collection plan– Data analysis plan

Results

• Pooled class data

• Graphs and tables

• Simple statistics

Discussion

• Contextualizing results, explaining sources of error, etc

Conclusions

• What did we find? Why does it matter?

Logistics

• Need 6 teams of 3 people

• Each team visits the garden over the next 6 weeks to record data

• We’ll analyze data all together and each person writes his or her own lab report

Need volunteers for these times

• Week 0: today• Week 1: Sept 3-9• Week 2: Sept 10-16• Week 3: Sept 17-23• Week 4: Sept 24-30• Week 5: Oct 1-7• Week 6: Oct 8-14

• Visit at your own discretion sometime that week