WRITING YOUR SUMMATIVE LAB REPORT

My minimum expectation for you is a level 5-6

CIS expects a minimum level 4.

These are the criteria you will be evaluated for each section

These are examples that you can use to understand EXACTLY what is required for each criteria you are evaluated on

Add a check once your writing matches the examples given and you have completed that criteria

Background Research

• Discuss: • What is resistance?• What is nichrome and why are we using it?• Controlled variables and their impact on resistance

should be explained in detail• Why is it important to know the resistance of materials

(in this case, resistance of metals)• Impacts on technology advancement, on humans/society

development, safety/efficiency or anything else that is interesting and relevant.

• Clear & detailed research question ends this section. • You must include independent & dependent variables

Referencing & Research

• Everything must be referenced. • Use MLA style – there are lots of websites that can help you with

this.

• Use reliable websites, preferably with an author and a date.

Prediction• Your hypothesis without any mention of ‘I’ or ‘we’

• If…then…because…. is the format you want.

Include reasons & research on independent and dependent variables and why it is worthwhile to investigate these

factors.

Variables• Use a table to help organize and keep everything nice and

neat.

• List your independent, dependent and controlled variables, explaining (briefly) why you are using them.

• Make sure you use how you are measuring them – this includes units!!

Procedures & Diagrams• It is good practice to have a labelled diagram of your set –

up.

• Components:• Figure # (1, 2, 3, etc)• Title• One sentence description of what the image shows.• See your textbook for an example

• It can be hand-drawn using a ruler or a photograph.

Observations• Qualitative – no numbers, what you saw• Quantitative – numbers, what you actually measured

• Use tables and tables must be numbered AND have a title, and an explanation of what the table has.

Analysis

• For this lab, you will have to use Excel to graph your data

• You will use the graph and interpret the different lines you have.

• You should have 5 lines for each of the wires, and ideally, at least 5 points to help you see the shape of the graph.

Types of Graphs to Expect

• If your factor was:

• Length • Your graph will be linear

• Thickness• Your graph will be non-linear

• You will have to do a ‘line/curve of best fit’.

• Each graph will have to have a:• Line drawn to find a trend (a pattern) and not connect

every dot• Figure #• Descriptive title (that is bold and underlined)• Axis labels • A legend or some sort of notation to help explain the

different lines• A sentence or two that describes what the graph is

showing (such as positive/negative trends, representation of variables, any general conclusion). • This is written after the title, and is not in bold or underlined

Axis Labels

• Include:• The variable• The unit it is

measured in brackets (unit)

• Underlined variable titles

Graph Trends – Linear Relationships

Direct Relationship Inverse Relationship

Graph Trends – Non-Linear Relationships

Positive/Direct Negative/Inverse

Graph Trends – No Trend

• When there is no relationship between variables, this means that your factor does not impact what you were measuring.

• Your hypothesis was not valid.

Strong v.s. Weak Correlation

Points are close to line of best fit Points are far from line of best fit

Line of Best Fit

Curve of Best Fit

Interpreting Line of Best Fit

LET’S PRACTICE!

MAKING GRAPHS IN EXCEL

Step 1• Enter your data,

include titles.

• Step 2: Click on the ‘Charts’ tab at the top

• Step 3: • Select

‘Scatter’.

• Choose smooth marked non-linear relationship

• Choose straight marked linear relationship

• Step 4: You will see your graph displayed, it will look something like mine.

Voltage

Current

• Step 5: Click on the coloured tab next to charts, and select ‘Chart Layout’

• Step 6: Click on one of the lines on your graph.

• Step 7: Select the option ‘Trendline’ and click on the very bottom, ‘Trendline Options’

• Step 8: Linear click ‘linear’. Non-linear select something that best fits your line. It will likely be ‘Power’

• Step 9: Go to ‘Options’ on the left. • Select ‘Set intercept = 0’, and ‘Display equation on

chart’

• Looking at the different graphing Options Linear

• Looking at the different graphing Options Logarithmic

• Looking at the different graphing Options Polynomial

• Looking at the different graphing Options Power

In the future,

you will have to choose the best graph yourself

• Step 10: You will see an equation next to your line of best fit. The number is what you must keep track of of.

• Step 11: Repeat steps 1-10 for each of your lines. You should have a total of 5 lines, one for each wire.

• Step 12:

• ‘Format’ options to ensure all axis are labelled.

Slope

This will have a larger slope (a higher number)

This will have a smaller slope (a lower number)

Slope• Run = independent = voltage• Rise = dependent = current

Ohm’s Law is R = V/I

• So, we will have to take the inverse of our slope value to get the resistance for each value.

You are required to show this work in a table and

explain why you had to do this step in your data analysis.

Analysis Explanation• You cannot rely on the graph to explain the data.

• You must use written explanation of your raw data and refer to the graph/tables to help the reader understand your explanation.

• You will explain and comment on the relationships you see between your independent and dependent variables for each of your wires.

You will use the words direct/inverse relationship & strong/weak correlation in your analysis.

Analysis Explanation

• For this lab, you should find the resistance for all 5 wires (ideally, they will all be different).• You will get this from the slope of the line.

• This is found from excel.

• The slope number in the equation is the inverse resistance if voltage is your independent variable.• You will make a table to illustrate your measured resistance for

each wire.

Calculated Resistances• You will take your calculated resistances from your graph

equations, and you will do two things with them:

• 1) Error Analysis. Look to the following slides for more information.

• 2) Graph calculated resistance against the gauge of wire to find the trend. For this, I will not be illustrating a graph, as this is something I’d like to see your understanding of.

Error Analysis• In your analysis, you will also do an error analysis.

• This is where you compare your results with results that are expected .• What is the theoretical resistance for that wire given by the

manufacturer

• This is done so you can discuss why your data looks the way it does in comparison to what is already known about that material’s properties.• It is also done to figure out where there may be issues in your

experiment (i.e. could your set up be better, did you need to consider other control variables, etc).

Percentage Error• You will use the formula:

Calculated Resistance

Theoretical Resistance

• You want your error values to be as close to 1 as possible• This means your calculated resistance is very close to what is

expected for that wire at that gauge/length

x 100%

Theoretical Resistance Data Chart

• Use this table for your theoretical resistance information.

• The wire we used was NiCr C

Outlier Points• Points that are very far away from your line of best fit, you

must explain what happened/causes it as part of your discussion of error

Conclusion• It is in paragraphs and has lots of detail!

• Error: if less than 10% error =>90%++ it means the experiment was successful at getting a valid answer

• Independent variable: Did you manipulate it in a fair way? Were there any inconsistencies or problems?

• Dependent variable: Did your experiment actually measure what you intended to measure? Could it have been measured in another way that would give better results?

• Control variables: were all variables controlled so it was a fair test? If not, how did that affect the results? Was there anything you could not control, or materials that could have been better?

• Does your data make sense?• Propose new areas to test to further get more information about

resistivity of the wires we studied.