Transcript Lesson 1 - churchillcollegebiblio

Range of Motion
IB SEHS
Internal Assessment
Internal Assessment
•
Lesson 1:
-pre-lab
-carrying out a standardised practical using handouts I will give you
-thinking about how you could adapt the experiment for an Internal Assessment
•
Lesson 2 and 3:
-Using your Design Lab Training Sheet you will work in teams to design a practical investigating an aspect
of osmosis.
•
Lesson 4 and 5:
-You will carry out the practical and collect data as a team.
•
Lesson 6 and 7:
-I will show you how to process your data with statistics!
-specifically using Excel to calculate means, standard deviations and draw graphs
•
Lesson 8 and 9:
-I will guide you on how to write a conclusion and evaluation
•
Lesson 10:
-Your practical will be handed in
-written up individually and in the correct format
-self assessment should be complete as well
Writing A Statement of the
Problem for the Experiment
What should it state?
It should state: “The Effect of the Independent
Variable on the Dependent Variable”.
A good statement of the problem for pur
experiment would be…..
The effect of a limited range of motion of the knee on
sprinting performance
More about our variables:
The independent variable is the variable that is
purposely changed. It is the manipulated variable.
The dependent variable changes in response to the
independent variable. It is the responding variable.
What is the “RoM” independent variable?
Knee brace
What is the dependent variable?
Sprinting time
Title for the photosynthesis
experiment
The effect of a limited range of motion of
the knee on sprinting performance
Another Look at Our Hypothesis
INDEPENDENT VARIABLE
If the RoM decreases,
DEPENDENT VARIABLE
then the sprinting time will increase.
To make this IB worthy you MUST:
a)Include a sketch graph of your predicted results
b) Give SCIENTIFIC reasoning as to why you predict this
Controls in an Experiment
Factors that are kept the same and not
allowed to change
What should be kept constant in the experiment?
• Age
• Gender
• Level of fitness
• Health/dietary issues
You MUST explain
-what affect each CV could
have on the reliability of the
results if not controlled
• Distance run and surface
• Intensity of run
• Construction of knee brace
• Outside air temperature
• Time of day
-how you are going to
control them
Values of the Independent Variable
How many different values of the
independent variable should we test?
Enough to clearly illustrate a trend in the data
Always have 2 populuations for dicontinuous data
(with one being the control)
e.g. smokers and non-smokers
Always use the 5x5 rule for continuous data
e.g. 10cm, 20cm, 30cm, 40cm, 50cm
Repeated Trials
How many repeated trials are needed in the experiment
Always have a minimum of 20 in each experimental group
for discontinuous data
Always have at at least 5 repeats for each range of the
independent variable
Drawing/photo of experiment
Place a cardboard
strip either side of
the knee to
stabilize it
Wrap the bandage around the
knee to hold the cardboard strips
in place thereby stabilizing the
joint
Writing a method
• EVERY step needs to be written with quantities,
equipment and uncertainties ALL specified
• You must take into account the ethical
considerations of carrying out a practical
• If you plan to use people in your experiment then
you MUST ask them to sign consent forms
Now complete your Design Lab sheet!
Carrying out your practical…
Qualitative Observations
(must have these or zero for DCP1!!)
•Pupils wearing looser clothing generally found it easier to
run faster
•All pupils started on a different foot
Quantitative: Sample Data Table
Title: The effect of changing glucose concentration on the rate of
respiration
Concentration of
glucose (%)
Vol of C02 produced in 5 min
(±0.01ml)
TRIALS
1
2
3
Mean Vol of C02
produced in 5 min
(±0.01ml)
10
3.00 5.00 4.00
4.00
20
4.00 5.00
6. 00
5.00
30
6. 00 7.00
5.00
6.00
40
7.00
8.00
6. 00
7.00
50
9.00
7. 00
8. 00
8.00
Data Processing for
Internal Assessment
AND Topic 1
Data Processing
• You need to:
1. Calculate the mean sprinting time for each
group
2. Calculate the error for EACH mean
3. Plot a graph comparing the times
Two classes took a recent quiz.
There were 10 students in each class
Each class had an mean score of 81.5
Since the means are the
same, can we assume that
the students in both classes
all did pretty much the
same on the exam?
The answer is… No.
The mean (mean) does not
tell us anything about the
distribution or variation in
the grades.
Here are scatter diagrams of the
grades in each class:
Mean
So, we need to come up
with some way of
measuring not just the
mean, but also the spread
of the distribution of our
data.
Why not just give an mean
and the range of data (the
highest and lowest values)
to describe the distribution
of the data?
Well, for example, lets say from
a set of data, the mean is 17.95
and the range is 23.
But what if the data looked like
this:
Here is the mean
And here is the range
But really, most of the
numbers are in this area,
and are not evenly
distributed throughout the
range.
The Standard Deviation is a
number that measures
how far away each number
in a set of data is from
their mean.
If the Standard Deviation is large,
it means the numbers are spread
out from their mean.
If the Standard Deviation is
small, it means the numbers are
small,
close to their mean.
Here are the
scores on
the biology
quiz for
Team A:
72
76
80
80
81
83
84
85
85
89
mean:
81.5
The Standard Deviation measures how far away each number
in a set of data is from their mean.
For example, start with the lowest score, 72. How far away is 72 from the mean
of 81.5?
72 - 81.5 = - 9.5
- 9.5
Or, start with the lowest score, 89. How far away is 89 from the mean of 81.5?
89 - 81.5 = 7.5
- 9.5
7.5
Now, lets compare the two classes
again
Team A
mean on the
Quiz
Standard
Deviation
Team B
81.5
81.5
4.88
15.91
6.1.3 State that the statistic standard deviation is used to summarize the
spread of values around the mean, and that within a normal distribution
approximately 68% and 95% of the values fall within plus or minus one or
two standard deviations respectively.
6.1.4 Explain how the standard deviation is
useful for comparing the means and the spread
of data between two or more samples.
• A small standard deviation indicates that the
data is clustered closely around the mean
value.
• Conversely, a large standard deviation
indicates a wider spread around the mean.
Now...how do you do it the easy way?
Concluding and Evaluating
•Conclusion
This is the section where you draw conclusions about the experiment
as it
relates to your aim and hypothesis.
Calculated results should be compared to values from the literature
(i.e. accepted values from professional laboratories) where possible.
This section should include:
• Conclusion based on your Aim or Hypothesis. (using appropriate
language)
• States the quantitative or qualitative relationship
• Correctly interprets the graph of the data
• Includes relevant calculated values to support conclusion
• Includes some elaboration based on the science being learned
Discussion of errors and limitations to
the experiment
• Must comment on the “quality” of the results, do they make sense?
• Identifies anomalous results where appropriate (use your SDs to help you
do this!)
• Prioritizes errors and suggests where they came from.
• Utilizes the ideas of “systematic” and “random” errors in the discussion
• Indicate what effect the error(s) would have on the results
• Human errors should not be the main source of errors!
• Suggestions for improvements
• Identifies weaknesses in the experiment and suggests realistic suggestions
for improvement
• Improvements should help to improve the errors previously identified
How to write an effective
conclusion
Also known as putting it all together
What is a conclusion?
• A conclusion is a summary of the experiment.
• It is putting the hypothesis together with the
data and coming up with a conclusion or
ending thought.
• It is a written answer to the original question.
So where to start…
• Every conclusion begins with a topic sentence.
• In a conclusion, the topic sentence is the
restatement of the problem/question.
Can your group state a hypothesis for
the research question below?
• The effect of different concentrations of
glucose solution on the rate of respiration?
Can you write a conclusion for the data below?
A graph showing the effect of different glucose concentrations on
the rate of respiration
14
12
Rate of respiration (CO2ml/min
10
8
6
4
2
0
0
0.5
1
1.5
2
2.5
Glucose concentration (%)
3
3.5
4
4.5
5
Keep your group’s conclusion close to
hand
• We will now go through step by step of the
format and information that should have been
included….
Our conclusion outline
1. Restate the Problem
This experiment was investigating the effect of
different concentrations of glucose solution on
the rate of respiration
Our conclusion outline
1. Restate the problem
2. Restate your hypothesis
(It was predicted that…)
It was predicted that as the concentration
increased from 0%, the rate of respiration will
increase up until the all respiration enzymes are
being used and their active sites are all
occupied. From this point on, the rate of
respiration will remain the same.
So was your hypothesis right, wrong or
indifferent?
3. Accept or reject your hypothesis
Does the data support the hypothesis?
If it does-we accept the hypothesis
If it doesn’t-we reject the hypothesis
My processed data supports my hypothesis
Now provide evidence
4. Provide actual data in sentence form that
backs up your previous statement.
• What type of relationship was there, if any?
– How did the independent variable effect
the dependent variable?
• Were there any trends?
• changes; (increases, decreases in data)
• patterns (repeated data that is similar)
Can you write a conclusion for the data below?
A graph showing the effect of different glucose concentrations on
the rate of respiration
14
12
Rate of respiration (CO2ml/min
10
8
6
4
2
0
0
0.5
1
1.5
2
2.5
Glucose concentration (%)
3
3.5
4
4.5
5
Our conclusion outline
As the concentration increased from 0% to 3%, the
rate of reaction also increased constantly from 1
CO2ml/min to 12 CO2ml/min until at 3% where
the rate of reaction reached it’s maximum of 12
CO2ml/min.
After this the rate of reaction remained constant at
12 CO2ml/min even though the glucose
concentration was increased to 5%
Next
5. Justify your data with scientific theory
• At low concentration of glucose, there is a steep increase in
the rate of reaction with increasing substrate
concentration. The active site of the enzyme is empty,
waiting for substrate to bind, for much of the time, and the
rate at which product can be formed is limited by the
concentration of substrate which is available.
• As the concentration of glucose increases, the enzyme
becomes saturated with glucose. As soon as the activesite
is empty, more substrate is available to bind and undergo
reaction.
• The rate of formation of product now depends on the
activity of the enzyme itself, and adding more substrate will
not affect the rate of the reaction to any significant effect
Our conclusion outline
1. Restate the problem
2. Restate your hypothesis
(It was predicted that…)
3. Accept or reject your hypothesis
4. Provide actual data in sentence form that
backs up your previous statement.
5. Justify your data with scientific theory
Yeah! We’re almost there….
6. Concluding sentence
• This sentence should
– Begin with a transition word
• To sum up
• In conclusion
• Therefore, it can be said that
– Rephrase the original question or problem
– Explain the importance of carrying out the
experiment
Our conclusion outline
In conclusion, it can be stated that
different concentrations of glucose do have
an effect on the rate of respiration
Therefore, it is possible to deduce the
optimum concentration for a respiratory
enzyme to ensure maximum efficiency of
this particular enzyme.
6 points to scientific success!
1.
2.
3.
4.
Restate the problem
Restate your hypothesis
Accept or reject your hypothesis
Provide actual data in sentence form that
backs up your previous statement.
5. Justify your data with scientific theory
6. Concluding sentence that justifies the
experiment
Conclusion
This experiment was investigating the effect of different concentrations of glucose solution on the rate of respiration
It was predicted that as the concentration increased from 0%, the rate of respiration will increase up until the all respiration
enzymes are being used and their active sites are all occupied. From this point on, the rate of respiration will remain the same.
My processed data supports my hypothesis
•
As the concentration increased from 0% to 3%, the rate of reaction also increased until at 3% where the rate of reaction
reached it’s maximum of 12 CO2ml/min.
•
After this the rate of reaction remained constant even though the glucose concentration was increased to 5%
This is because
•
At low concentration of glucose, there is a steep increase in the rate of reaction with increasing substrate concentration.
The active site of the enzyme is empty, waiting for substrate to bind, for much of the time, and the rate at which product
can be formed is limited by the concentration of substrate which is available.
•
As the concentration of glucose increases, the enzyme becomes saturated with glucose. As soon as the activesite is empty,
more substrate is available to bind and undergo reaction.
•
The rate of formation of product now depends on the activity of the enzyme itself, and adding more substrate will not
affect the rate of the reaction to any significant effect
In conclusion, it can be stated that different concentrations of glucose do have an effect on the rate of respiration
Therefore, it is possible to deduce the optimum concentration for a respiratory enzyme to ensure maximum efficiency of this
particular enzyme.
Evaluation
To evaluate your science experiments simply answer the following
questions:
•
How could you have improved the way you did your practical?
•
What improvements would you make to your method if you
did it again? Why?
•
Did the data you collected give you enough information? Why?
•
What could you do to improve the reliability of your data?
Evaluations : What to include...
Examples...
1) Write down how well you think the
experiment went and why.
2) "The experiment went quite well but my
human error contributed to unreliable
results. This is because….".
3) Point out any odd results that you
had
• "Looking at the graph/standard deviations
anomalous results can be identified. These
are….”
4) Explain why IN DETAIL, you may
have some odd results / what
problems you had with the
experiment.
• Include MINIMUM THREE and it MUST refer
back to the method
• "One of the reasons that these large standard
deviations/anomalous results were obtained
could be due to not using the same starting
position, which meant that some participants
had an advantage in terms of distance they
had to cover…
5) Explain how you could improve the
experiment if you had to do it again IN
DETAIL. Suggest AT LEAST THREE things.
Include a diagram and explain why.
• "The experiment could be repeated using the
same starting position for all participants
6) Explain what further experiments
you could do in the future, if you had
the time.
• "If this investigation could be extended, the
effect of limiting the RoM of the elbow joint
would compliment the data obtained in this
experiment.. This could be done by…"