SCIENTIFIC INVESTIGATION

1.1 Analysing method of scientific investigation

1.2 Planning an experiment

What is the scientific investigations??

• When scientist carry out their work, they begin by observing natural phenomena , a process or an event around them.

• Then, they follow a series of step called scientific methods/ scientific investigation

• In order to find possible answer

Steps of scientific method

1. Identifying the problem

-by observe of specific natural phenomenon by using 5 senses

-and ask question about what they observed in nature

-and actively seek answer

-scientific answer need to be answered by gathering evidence

-so we need to run the experiment

2. Identifying and controlling variables

-consist of manipulated variable/independent variable( what experimenter change during exp)

-responsive variable/dependent variable(what experimenter measures )

-constant variable/standard variable (things that are kept equal/stardardized/constant)

-control group(when independent variable eliminated)

Ex-

You water 3 sunflower with salt water. Each plant receives a different concentration of salt solutions. A fourth plants receives pure water. After a two week periods, the height is measured.

Can you give me….

Manipulated variable(MV)=

Responsive Variable(RV)=

Constant Variable(CV)=

Control Group(CG)=

• Assignment !! =P

3. Forming a hypothesis-general statement about observed event

-not valid yet

-if valid will become theory

-relationship between MV and RV.

Ex: can be worded as an

If…………….Then

If I used the higher concentration of salt solution to water the plant, then the height of the plant will become higher.

@ the higher concentration of salt solution to water

the plant, the height of the plant will become

higher.

4. Planning the investigations-plan and run the experiment

5. Collecting, analysing and interpreting data

-data obtained by means of observation and measurement

-presented in the form of graph, table or diagrams

-find a relationship between MV and RV -Based on information gathered from the exp

6. Make a conclusion

- state the conclusion, whether you want to accept or reject the hypothesis.

- the higher concentration of salt solution to

water the plant, the height of the plant will

become higher.

7. Write a report

Title:Effect of the load of school bag on the rate of heartbeat of students

Objective:To study the effect of the load of school bags on the rate of heartbeat of students

Problem Statement: What is the effect of the load of school bags on the

rate of heartbeat of students?

Hypothesis: The heavier the load of school bags,the faster the rate of heartbeat of students

• Variables MV: Load of school bagsRV: rate of heartbeatCV: distance of movement

• Materials and apparatus: Material: Books, School bagsApparatus: Weighing scale and stopwatch

Technique: Calculating the rate of heartbeat

Procedure: The students are divided into 4 groups etc

Result : Bar graph is coded

Discussion : The heavier the school bag , the faster the heartbeat

Conclusion: When the load of the school bag increases, the rate of heartbeat also increases, Hypothesis accepted

Lets do simple experiment!

Thumb wrestling

Question: Which trait is best to help someone win a thumb war tournament?

Hypothesis: If…………………………………...Then…………………………………..

Materials:………………………………….

Procedure:

1. To play the game, a player hooks the four finger of the other player right hand and clasps firmly.

2. To start the game both student say “ one, two, three four, I declare a thumb war.”

3. Both students try to trap or capture the opponent’s thumb for 3 seconds to win.

4. Females play females. Males play males.

5.Students can conduct only one thumb war per round. No cheating!!

6. Twisting the opponent’s arm, use the opposite hand or use another finger is not allowed

7. Students should not hurt the other student.

Experiment data:

Your measurement:Your measurement

Wrist: Thumb circumference:

Thumb length:

Male winner Wrist: Thumb circumference:

Thumb length:

Female winner

Wrist: Thumb circumference:

Thumb length:

Variables:

MV:……………………..

RV:………………………

CV:………………………

Analysis: create a bar graph with the wrist , thumb length and thumb circumference of male winner, female winner.

Conclusion: What trait was the most important for winning?.....................................................

What were the experimental errors in this experiment?

…………………………………………………

There were three MV in this experiment. Did you have the same conclusion as all the other students in the class?

……………………………………………If not, having three MV cause the class to

have inconsistent result? …………………………………………

True or False: Scientific experiments try to have only one MV?

………………..

• Pass up your assignments on next week at the same period we were doing the experiment.

End of the chapter 1!!