6 THE NATURE OF SCIENCE

(1)

THE NATURE OF

SCIENCE

(2)

STATISTICS

 STATISTICS: COLLECTING,

(3)

CHI-SQUARE

 CHI-SQUARE: A TEST USED IN

STATISTICS TO COMPARE

OBSERVED DATA WITH DATA WE WOULD EXPECT TO OBTAIN

(4)

CHI-SQUARE

 FORMULA:

 X2 = (O-E)2 / E

 CHI-SQUARE EQUALS OBSERVED

(5)

CHI-SQUARE

 ARE MY RESULTS, THE

DIFFERENCES BETWEEN THE EXPECTED RESULTS AND THE

(6)

CHI-SQUARE

 CHI-SQUARE IS TESTING THE NULL

HYPOTHESIS: THERE IS NO SIGNIFICANT DIFFERENCE

BETWEEN THE EXPECTED AND OBSERVED RESULTS.

 PERFORM A M&M CHI-SQUARE

(7)

STATISTICS

 WE HAVE THE FOLLOWING DATA:  2, 6, 3, 2, 5, 9, AND 8

 WHAT IS OUR SAMPLE SIZE?  7

 WHAT IS OUR AVERAGE/MEAN

 ADD THE NUMBER = 35 AND DIVIDE

(8)

STATISTICS

 STANDARD DEVIATION IS THE MEAN

OF THE MEAN.

 MOST DATA ARE CLOSE TO THE

AVERAGE, FEW TEND TO BE IN ONE EXTREME OR THE OTHER. MOST WILL HAVE A BELL CURVE SHAPE.

 THE STANDARD DEVIATION TELLS

YOU HOW TIGHTLY ALL THE DATA

(9)

(10)

STANDARD DEVIATION

 LOOK AT THE FOLLOWING DATA:

 2, 4, 4, 4, 5, 5, 7, 9

 HOW DO WE CALCULATE THE MEAN?

 n=8 THIS IS OUR SAMPLE

 THE SUM OF THE DATA IS 40 DIVIDED BY THE SAMPLE SIZE OF 8.

(11)

STANDARD DEVIATION

 FIND THE DIFFERENCE OF EACH DATA POINT

FROM THE MEAN; SQUARE EACH RESULT:

 (2-5)2 = 9, (4-5)2 = 1, (4-5)2 = 1, (4-5)2 = 1,

(5-5)2 =0, (5-5)2 = 0, (7-5)2 = 4, and (9-5)2 = 16

 CALCULATE THE MEAN OF THESE VALUES:

 9+1+1+1+0+0+4+16 / 8 = 4

(12)

METRIC SYSTEM

 THERE ARE FIVE MEASUREMENTS

TO KNOW:

1. LENGTH 2. MASS

3. VOLUME 4. DENSITY

(13)

METRIC SYSTEM

 LENGTH:

 MOST OF THE MEASUREMENTS

HAVE WHAT WE CALL A BASIC UNIT. IF YOU KNOW THE BASIC UNITS YOU CAN CONVERT EASIER.

 KNOW THAT THE BASIC UNIT FOR

(14)

METRIC SYSTEM

 KNOW THAT 1 METER EQUALS 39.4

INCHES.

 EXAMPLE: 6 FOOT 1 INCH TO METERS.

 FIRST, CHANGE FEET TO INCHES.

6X12 PLUS 1 EQUALS 73 INCHES.

 DIVIDE 73 BY 39.4 INCHES AND IT

(15)

METRIC SYSTEM

 FOR OBJECTS SMALLER THAN A

METER WE USE THE CENTIMETER.

 KNOW THAT 1 METER EQUALS 100

CENTIMETERS

 METERS X 100 EQUALS

(16)

METRIC SYSTEM

 FOR MEASURING LONG DISTANCES WE

USE THE KILOMETER. KILO MEANS 1,000.

 KNOW THAT 1,000 m EQUALS 1 km

 TO CONVERT (m) TO (km) DIVIDE BY

1000.

 1.85 m TO km EQUALS 1.85/1000 WHICH

(17)

(18)

METRIC

 VOLUME:

 THE BASIC UNIT FOR VOLUME IS

THE LITER DESIGNATED BY L.

 POINT OF REFERENCE FOR LITERS:

(19)

METRIC

 TO MEASURE VOLUMES SMALLER

THAN A L WE USE MILLILITERS OR (ml)

 1L = 1000 ml

(20)

(21)

METRIC SYSTEM

 MASS:

 THE BASIC UNIT FOR MASS IS THE

KILOGRAM OR Kg.

 THE POINT OF REFERENCE IS 1Kg =

(22)

METRIC SYSTEM

 FOR MEASURING THE MASS OF

SMALLER OBJECTS WE USE GRAMS SIGNIFIED BY A g.

 1Kg = 1000g

 KILOGRAMS TO GRAMS: MULTIPLY

(23)

METRIC SYSTEM

 CONVERT 250 POUNDS TO Kg.

 250/2.2 EQUALS 113.6 kg.

 CHANGE 113.6 kg TO GRAMS:

(24)

(25)

METRIC SYSTEM

 DENSITY:

 THE FORMULA FOR DENSITY IS

D=M/V.

 PROBLEM: 1 Kg OBJECT, SV 500 ML

(26)

METRIC SYSTEM

 TEMPERATURE:

 TEMP IS MEASURED USING THE

(27)

METRIC SYSTEM

 F TO C: F – 32 X 5/9 = C  C TO F C X 9/5 + 32 = F

 CONVERT 100 DEGREES

FARENHEIGHT TO CELSIUS

 CONVERT 40 DEGREES CELSIUS TO

(28)

METRIC SYSTEM

 100-32 EQUALS 68 TIMES 5/9 WHICH

IS .55 EQUALS 37.4 DEGREES CELSIUS.

 40 TIMES 9/5 WHICH IS 1.8 EQUALS

(29)

METRIC SYSTEM

1. CHANGE 7 FEET INTO METERS 2. CHANGE 7 FEET INTO CM

3. CHANGE 7 FEET INTO KM

 2.13 m  213 cm

(30)

METRIC

 CHANGE 200 POUNDS TO kg

 90.9 kg

 CHANGE THAT NUMBER TO g

(31)

METRIC SYSTEM

 WHAT IS THE DENSITY OF A 2 kg ROCK

(32)

METRIC SYSTEM

 CHANGE 120 DEGREES F TO C

 120 – 32 X .55 EQUALS 48.4

DEGREES C

 CHANGE 60 DEGREES C TO F

(33)

SIGNIFICANT FIGURES

 When adding or subtracting numbers, count

the NUMBER OF DECIMAL PLACES to determine the number of significant figures. The answer cannot CONTAIN MORE

PLACES AFTER THE DECIMAL POINT THAN THE SMALLEST NUMBER OF

DECIMAL PLACES in the numbers being added or subtracted.

(34)

THE NATURE OF SCIENCE

 EMPIRICAL: KNOWLEDGE

ACQUIRED BY OBSERVATION OR EXPERIMENTATION.

 QUALITATIVE: DESCRIPTIONS OR

DISTINCTIONS BASED ON A QUALITY OR CHARACTERISTIC RATHER THAN A QUANTITY OR MEASURED VALUE.

 QUANTITATIVE: STATISTICAL,

(35)

SCIENTIFIC METHOD



Scientists use the scientific

(36)

(37)

SCIENTIFIC METHOD

There are six major steps:

1. State the problem 2. Form a Hypothesis 3. Gather data

4. Perform experiment

(38)

SM

1. State the problem

 The problem is what you want to know.  The problem is stated in the form of a

(39)

SM

2)Form a hypothesis:

The hypothesis is what you think is going to happen.

(40)

SM

3. Gather data:

Find out all there is to know about the topic, educate yourself.

4. Plan and perform an experiment

5. Record and analyze your results

(41)

SM

 YOU NEED TO TEST YOUR

HYPOTHESIS BY DOING A

CONTROLLED EXPERIMENT. THIS MEANS THAT ALL VARIABLES THAT CAN EFFECT YOUR EXPERIMENT REMAIN CONSTANT OR

(42)

SM

 WHEN GRAPHING:

 THE INDEPENDENT VARIABLE GOES

ON THE X AXIS.

 THE INDEPENDENT VARIABLE IS

WHAT YOU HAVE CONTROL OVER.

 THE DEPENDENT VARIABLE GOES

ON THE Y AXIS.(LITTLE OR NO

(43)

(44)

THE NATURE OF SCIENCE

 CONCENTRATE ON GETTING

ACCURATE DATA. SUCH EVIDENCE IS OBTAINED BY OBSERVATIONS

(45)

THE NATURE OF SCIENCE

 THE PROCESS OF FORMULATING

AND TESTING HYPOTHESES IS ONE OF THE CORE ACTIVITIES OF

(46)

THE NATURE OF SCIENCE

 THE ESSENCE OF SCIENCE IS

VALIDATION BY OBSERVATION.

 WHEN FACED WITH A CLAIM THAT

SOMETHING IS TRUE, RESPOND BY ASKING WHAT EVIDENCE

(47)

THE NATURE OF SCIENCE



NO GOOD HYPOTHESIS CAN

BE DEVELOPED WITHOUT

RESEARCH INTO THE

(48)

THE NATURE OF SCIENCE

 THE SCIENTIFIC METHOD IS A

PROCESS OF USING CRITICAL THINKING.

 THINGS THAT ARE NOT TESTABLE

IN SOME SCIENTIFIC OR

(49)

THE NATURE OF SCIENCE

 ONCE THE HYPOTHESIS HAS BEEN

ESTABLISHED, IT IS TIME TO TEST IT.

 AN EXPERIMENT IS DESIGNED TO