Unit 4: Observation & Experiment

Front 1

For induction to be considered valid (reliable)

Back 1

1. Argument has to be strong (many true observations)

2. Premises have to be acceptable (observations made under different, representative conditions)

3. Conclusion has to take into account all observations on which it is based (noexceptions).

Hint 1

specific to general

Front 2

For deduction to be valid (sound)

Back 2

1. Argument has to be valid (logical)

2. Premises (hypothesis and test) need to be ‘true’ (to the best of your knowledge).

Hint 2

general to speciific

Front 3

spontaneous generation

Back 3

the idea that non-living material can produce life- magically appears

Aristotle

Front 4

francesco reddi

Back 4

performed experiment to see if rotting meat turn into flies

Front 5

What is an observation?

Back 5

An observation is the act or process of usingone’s senses in order to acquire information.

Front 6

What is an inference?

Back 6

When you infer, you make a mental judgmentbased on observations. Inferences cannot bedirectly observed. They require thought.

Hint 6

For example, if you get up in the morning, lookup at the sky and observe dark clouds, observethe air is cool and humid, and observe puddleson the ground, you might infer that it hasrecently rained.

Front 7

Scientific Observation

Back 7

is a method of data collection for research purposes, observation is more than just looking or listening.

Any data recorded during an experiment can be called anobservation.

Front 8

Validity of observations

Back 8

Observations have to be accurateand precise to be valid

Front 9

Accuracy

Back 9

is the degree of conformity of a measured or calculated quantity to its actual (true) value.

Hint 9

expected result

Front 10

Precision,

Back 10

also called reproducibility or repeatability, is the degree to which further measurements or calculations will show the same or similar results.

Hint 10

low variance

Front 11

To increase validity of observations:

Back 11

Repeatability - the variation arising when allefforts are made to keep conditions constant byusing the same instrument and operator, andrepeating during a short time period

Reproducibility - the variation arising using thesame measurement process among differentinstruments and operators, and over longer timeperiods.

Front 12

Research

Back 12

(a scientific inquiry) uses inductive reasoning. A scientific inquiry is an orderly procedure carried out to suggest a hypothesis or make a conclusion.

Front 13

An Experiment

Back 13

uses observations to reach a conclusion. An experiment uses deductive reasoning. An experiment is an orderly procedure carried out with the goal of supporting or refuting the validity of a hypothesis.

starts with a hypothesis

An experiment is a reasonable test that woulddisprove the hypothesis if it were false. If thehypothesis gets tested and cannot be proven wrong, wesay it is supported.

Front 14

If your hypothesis gets tested among the scientificcommunity and widely accepted it becomes a...

Back 14

theory.

Front 15

When the scientific community stops arguing aboutyour theory, it becomes

Back 15

law

Front 16

Instrumentation

Back 16

Can be demonstrated that sensoryobservations are not completely reliable

To improve reliability of observations

- must use trained observers

- free them of sensory input

Instrumentation provides a means ofobtaining more objective data than thatprovided from sensory experience

Front 17

Examples of scientific instruments

Back 17

Microscope

Telescope

Voltmeter

Stop watch

Metre rule

Electronic scales

Seismometer

Volumetric flask

Magnetometer

Mass spectrometer

Spectrophotometer

MRI Machine

Sphygmomanometer

Infra-red spectrometer

RadarLidar

Front 18

Acceptability of scientific observations

Back 18

1. Instruments may introduce their ownparticular bias or error into observations oroperator may not use instrument correctly

2. Effect can be minimized by using manydifferent instruments and many differentobservers in the same situation

3. For observation to be acceptable it must fitprevailing theories

Front 19

Experimentation

Back 19

Involves controlled observation

Insofar as possible, all variables held constantexcept for the one being tested:

Front 20

independent variable –

Back 20

the one which is adjusted by the experimenter

Front 21

controlled variables -

Back 21

these are variables that could affect the outcome of the experiment, which you make the same each time. You control these variables, by making them the same for every test, so you know they're not affecting the result.

Front 22

dependent variable –

Back 22

the variable whose quantity responds to changes in the independent variable

Front 23

Experimentation– the work of William Harvey

Back 23

Considered to be the fatherof modern medicine

theorized that blood flows out of the heartinto arteries and returns to the heart viathe veins.

He carried out experiments whichshowed that blood can only flow in onedirection in the veins – towards the heart. valve

Front 24

Galileo – father of modern science

Back 24

weight is mot a determinig factor when compared how fast an object will meet the ground