Lesson 3
Strategies employed
1.Connect (Hook and Hold) (5 mins)
+ Introduce students to the idea that a
scientific hypothesis consists of 3 major variables: Independent, dependent
and constant variables. Using these variables, they are to craft their
hypothesis.
2.Acquire and Make meaning (Receive
Knowledge and skills, and understanding learning outcomes) (40 mins)
+ Students will be directed to write their Group Research Proposal by using this link: http://1drv.ms/1OEXK7g or https://drive.google.com/drive/u/0/folders/0Bw72rpuy2MMLa2FXU2k1RkhGd1U
+ Refer to the website
http://www.sciencebuddies.org/sciencefairprojects/project_variables.shtml#whatarevariables
+ Students are required to identify the following of their research question:
• (a) Independent
variables
• (b) Dependent
variables
• (c) Control
variables
+ They are to post these 3 variables into
their blogs.
+ The students are now required to write
their hypothesis in their blog page.
They can refer to the guide here:
http://www.sciencebuddies.org/sciencefairprojects/project_hypothesis.shtml
An example is found in the ISS Blog page
below for students to understand the relationships between the variables and
hypotheses.
3.Transfer (Formative checks,
reflections, etc.) (5 mins)
+ They must post their hypothesis
according to the correct format as demonstrated in the examples below.

There are 6 types of
research, so 6 examples are given below:
Question 1: Test a Hypothesis
Different brands of handphones are tested
for the radiation that they emit during standby, dial mode and receive mode.
(a) State the independent
variable [1]
different
brands of handphones
(b) State the dependent
variable [1]
Radiation
emitted from different handphones
(c) Suggest a hypothesis
[1]
Samsung
handphones have the greatest amount of radiation emitted
(Note: There are no right or wrong answer
but it is just a guess in formulating hypothesis)
(d) State 3 variables that you should keep
constant. [3]
Handphones
should be fully charged.
Handphones
should be of the same battery capacity
Handphones
should be brand new
Question 2: Measure a
value
The mass of jupiter is
calculated using the following steps:
 Take pictures of Jupiter and its 4 moons every night over 30 days through a telescope at 8 pm.
 Plot a graph of the position of each of the 4 moons over 30 days.
 Determine the period of each of the 4 moons.
 Measure the distance between the moons and the center of jupiter from the xt graphs.
 Plot a graph of T^2 against r^3.
 Calculate the gradient.
 Let gradient = 4pi^2/GM and calculate M since G is known.
 Calculate the percentage error of the value of G.
(a) State
the independent variable. [1]
the
radius of different jovian moons from the center of jupiter
(b) State
the dependent variable. [1]
the
period of each of the jovian moons
(c) Suggest
a hypothesis [1]
The
mass of jupiter determined should be 1.898 × 10^27 kg and have a percentage error of less than 5%.
(Note: There are no
right or wrong answer but it is just a guess in formulating hypothesis)
(d) State 3 variables
that you should keep constant. [3]
All
the photographs should be taken with the same magnification.
All
the photographs should be taken at the same time.
All
the photographs should be taken with the same sky conditions (e.g. clear
skies)
Question 3: Finding relationships
The rebound rating is the ratio of the
height the ball bounces to, divided by the height the ball was
dropped from. Use the rebound rating to measure the bounciness of new
tennis balls vs. balls that have been used for 10, 20, 50, and 100 games.
(a) State the independent
variable. [1]
the
number of times the tennis balls have been used
(e.g.
0, 10, 20, 50, 100 games)
(b) State the dependent
variable. [1]
The
rebounce ratio
=
height of rebounce / height where tennis ball is dropped
(c) Suggest a hypothesis.
[1]
The
more times the tennis ball is used, the lower is the rebounce ratio
OR
The
more times the tennis ball is used, the higher is the rebounce ratio
(Note: There are no right or wrong answer but
it is just a guess in formulating hypothesis)
(d) State 3 variables that you should keep
constant. [3]
Height
at which the tennis ball is dropped.
The
tennis ball must be dropped vertically downwards.
There
should not be any draft that may cause the falling tennis ball to drift.
Question 4:
Mathematical Modelling
It is observed that
when a ball bearing falls down a column of water, the speed increases but up to
a point. In order to create a Mathematical Model of the phenomenon, the
following steps were taken:
·
A high
speed video is taken of the ball bearing falling down the cylinder
·
Using the
video motion analysis software, a graph of velocity against time is created
·
As it looks
like a graph of V = A  Be^(Ct + D), it was used to fit the data
·
The
coefficient of fit will tell us how close is the graph to the data
(a) State
the independent variable. [1]
Time
from the point at which the ball bearing is released.
(b) State
the dependent variable. [1]
The
velocity of the ball bearing.
(c) Suggest
a hypothesis. [1]
The
velocity of the ball bearing varies with time in the following relation of V =
A  Be^(Ct + D)
(Note: There are no right
or wrong answer but it is just a guess in formulating hypothesis)
(d) State 3 variables
that you should keep constant. [3]
Height
at which the ball bearing is dropped.
The
ball bearing must be dropped vertically downwards.
The
temperature of the experiment must be the same.
Question 5: Observational and Observatory
Research
A curious student wants to find out the
soil quality around the school compound.
(a) State the independent
variable. [1]
Different
locations around the school.
(b) State the dependent
variable. [1]
The
soil quality (e.g. Nitrates, Phosphorous, Potassium)
(c) Suggest a hypothesis.
[1]
The
soil quality around the school is about the same.
(Note: There are no right or wrong answer
but it is just a guess in formulating hypothesis)
(d) State 3 variables that you should keep
constant. [3]
Depth
at which the soil sample is collected.
Amount
of soil collected at each site.
Weather
must be the same during the collection of sample.
Question 6: Industrial
and Applied Research
An innovative student
wants to build an automatic attendance taking machine.
(a) State the market
need or problem statement. [1]
Currently,
attendance taking has to be done manually or by scanning the thumb print or
scan an identity card on a machine. All these actions are time consuming and
requires additional logistics such as an attendance sheet or electronic
scanner.
(b) State the engineering
goal. [1]
To
develop a proximitybased sensor that can take attendance of a class without
any action by the teacher.
(c) State 3 design
specifications of this prototype. [3]
There
should be a display screen.
The
device should be handy and easy to carry.
The
device will be able to detect the sensor card from 50 meters away.
(d) Explain how do you
prove that you have achieved your engineering goal. [1]
Carry
out a Trial Test to see how many percent of the attendance is captured by the
device and compare it with manual attendance taking.
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