Skill companion: Analysing Data and Anomalies (Year 8)

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Skill companion · Year 8 Science Inquiryseegongsik /au

Analysing Data and Anomalies: a skill companion

A small set of reusable sheets that grow one inquiry skill: describing a pattern, trend or relationship in full (its direction, shape, size and range), telling ordinary measuring scatter from an anomaly, deciding what to do about an anomaly, and stopping a description before it claims more than the data shows. Print the scaffolds once and slot them into the science lessons you already teach.

AC9S8I05

analyse data and information to describe patterns, trends and relationships and identify anomalies

What a skill companion is

Inquiry skills are not a topic of their own. They grow inside the science units a class teaches all year, wherever results come in: cell counts, heart rates, earthquake records, rock samples, bounces, salts and reactions. So this pack is not a full term of lessons. It is three reusable scaffolds, a map of where they fit, and a short stand-alone lesson for teaching the skill on its own first.

Start here: five minutes

Read the pairing map on the next page: it shows which scaffold fits which science lesson.
Print the relationship sheet whenever results need describing, and the noise sheet whenever a reading looks odd.
Cut out the cards once. They are reused all year, and the blank cards fit any topic.
Open the free interactive unit on your board when you want a worked example of the skill.
Run the one-page mini-lesson first if you want to teach the skill before folding it into a topic.

The step up from Year 7

In Year 7 students described a pattern with a number and picked out an odd trial. In Year 8 they describe the whole shape of a relationship, including where it changes (steady, then levelling off), and they judge an anomaly by how far it sits from the trend compared with the ordinary scatter of the other readings. A small wobble is noise, not a new pattern; a point far outside the scatter is checked and remeasured, never deleted; and a description stays inside the range measured and does not claim a cause.

On the board

This pack is the printable half of a free interactive unit. On screen, students read “Mass and volume of granite, read three ways” as a table, a bar chart and a line graph, click the point in “Find the rate that breaks the trend”, sort statements with “Supports” and “Does not support” in “Which descriptions does the data support?”, and add readings one by one in “Watch the cooling trend take shape, point by point”.

seegongsik.com/au/y8/inquiry/AC9S8I05

Aligned to the Australian Curriculum V9 (AC9S8I05). This pack is original material from seegongsik, independently produced and not endorsed by ACARA. Curriculum content descriptors are (c) ACARA, licensed under CC BY 4.0. Free to print and use in class.

Where the skill fitsPairing map

Slot the skill into your science lessons

Every set of results in Year 8 needs describing, and most have a reading worth a second look. This map shows data in each Year 8 topic, the pattern to describe, what an anomaly might look like there, and which scaffold to reach for.

When you teach	Data to analyse	The pattern to describe	A possible anomaly	Scaffold
Cells: the Basic Units of Life (AC9S8U01)	Cells counted across the field of view at three magnifications	Fewer cells across as the magnification rises	A count from a slide that was thicker or folded	Noise sheet
Cells, Tissues and Organ Systems (AC9S8U02)	Heart rate each minute after exercise	A fast fall, then flattening	A count taken while the student was talking or moving	Relationship sheet
Plate Tectonics (AC9S8U03)	Earthquakes plotted by distance from a plate boundary	Far more close to boundaries than away from them	A deep earthquake far from any boundary, worth checking in the record	The cards
The Rock Cycle (AC9S8U04)	Mass lost by chalk shaken in a jar	A steady rise with shaking time	A piece that chipped, or a reading taken while the chalk was wet	Noise sheet
Kinetic and Potential Energy (AC9S8U05)	Bounce height for each drop height	Close to a straight line, a little below proportional at the top	A drop onto a different patch of floor	Noise sheet, then the cards
Elements, Compounds and Mixtures (AC9S8U06)	Masses of salt recovered from salty water of different strengths	More salt from stronger solutions, in step	A dish weighed before the salt was fully dry	Relationship sheet
Physical and Chemical Changes (AC9S8U07)	Temperature drop for each mass of bicarbonate of soda	Steady, then levelling off when the vinegar runs out	A reading taken before stirring finished	The mini-lesson, then the relationship sheet
Any science topic	Any results in pairs of numbers	Direction, shape, size and range	A point far outside the scatter of the rest	Relationship sheet first

The three moves, and the picture that backs each one

When you want a worked example on the board, open the interactive unit and use the picture that matches the move.

Read a relationship from a graph, with its rate: “Mass and volume of granite, read three ways”.
Find the point that breaks a trend: “Find the rate that breaks the trend”.
Keep a description inside the data: “Which descriptions does the data support?” and “Watch the cooling trend take shape, point by point”.

How the scaffolds build the skill

The relationship sheet works out the steps in two data sets and writes a full description of each, including where the pattern changes. The noise sheet compares each reading with a trend line, sets the size of the ordinary scatter, and decides what to do about the one reading far outside it. The cards sort statements into sound descriptions, noise read as a pattern, and claims that reach too far.

Scaffold 1 · Relationship sheetOne per student

Describe the whole relationship

NameClassDate

A full description says four things: the direction (rises or falls), the shape (steady, speeding up or levelling off), the size (by about how much for each step) and the range (between which values you measured). Work out the steps first; they show the shape.

A. Heart rate after skipping

Minutes after	0	1	2	3	4	5	6
Heart rate (beats/min)	152	128	110	98	90	85	82
Step from the last	–

Frame: As the time after exercise rose from ___ to ___ minutes, the heart rate ___ , quickly at first and then ___ .

B. Bicarbonate of soda in 50 mL of vinegar

Powder (g)	1	2	3	4	5	6
Temperature drop (°C)	1.2	2.5	3.6	4.8	5.1	5.2
Step from the last	–

Frame: Up to ___ g, the drop grew by about ___ °C for each gram. After that, ___ .

Why might the pattern change at that point?

C. Check your descriptions

□ Direction: rises or falls□ Shape: steady, speeding up or levelling off□ Size: about how much for each step□ Range: the values measured, and no further

Scaffold 2 · Noise or anomaly?One per student

Noise or anomaly?

NameClassDate

Real readings never sit exactly on the trend line; they scatter a little either side. That scatter is noise. An anomaly is a reading much further from the line than the ordinary scatter of the others. Measure each reading’s distance from the line before you decide.

A. The chalk record

Pieces of chalk were shaken in a jar and weighed after each shaking time. The dashed trend line is mass lost = 0.5 × time.

Time (min)	0	2	4	6	8	10	12
Measured (g)	0.0	0.9	2.1	2.9	5.6	5.0	6.1
Line predicts (g)
Difference (g)

B. Decide

Most readings sit within ___ g of the line. That is the noise.

The reading far outside the noise (time and value):

Two things that might have caused it:

What we do: keep it, mark it, and

Does the anomaly change our description of the trend? Why?

Scaffold 3 · Description cards (cut out)Reuse all year

Sound, noise, or too far?

Cut out the cards. Lay down the three grey heading cards, then sort the statements under them. Ask of each one: is the pattern bigger than the scatter, and does the claim stay inside the data?

Sound descriptionSays the direction, shape and size of the pattern, within the range measured.Heading

Reads noise as a patternTreats a small wobble, the size of ordinary measuring scatter, as if it meant something.Heading

Reaches too farClaims a cause, or stretches the pattern beyond the data.Heading

As the shaking time rose from 0 to 12 minutes, the mass lost rose by about 0.5 g every minute.Card A

Repeat readings of 29.8, 29.3 and 30.4 °C show the salt warms the water differently each day.Card B

The 30-second pulse counts went 36, 35, 37, so the heart sped up on the third count.Card C

The temperature drop will keep growing by about 1.2 °C for every extra gram, even with 50 g of powder.Card D

In the data set, earthquakes were far more common within 100 km of a plate boundary than further away.Card E

Heart rate fell quickly in the first two minutes after exercise, then more and more slowly.Card F

The bounce from 60 cm was 1 mm lower than the line, so balls bounce worse from 60 cm.Card G

Our granite samples were 2.7 g per cubic centimetre, so every rock on Earth has this density.Card H

The temperature drop grew steadily up to 4 g of powder, then stayed near 5 °C.Card I

Ice cream sales and sunburn cases rise together, so ice cream causes sunburn.Card J

The mass lost at 6 minutes was 0.1 g under the line, so shaking must slow down after 4 minutes.Card K

Across the five granite samples, mass rose in step with volume, about 2.7 g for every cubic centimetre.Card L

A description of your own results:

Write your own

A description of your own results:

Write your own

A description of your own results:

Write your own

Teacher note: the piles are not the same size. The answer sheet lists which card is which, and why.

Mini-lesson · Teacher planAbout 30 minutes

Pool it, describe it, question the odd one

Use this stand-alone lesson to teach the skill on its own, before you fold it into a science topic. Groups time ten swings of a pendulum at four lengths and the class pools the times on the board. The pooled times show a relationship that rises and flattens, an ordinary scatter between groups, and usually one time far outside it.

We are learning to

describe a relationship by its direction, shape, size and range,
tell ordinary measuring scatter from an anomaly,
decide what to do about an anomaly without deleting it.

Success criteria

I can write one sentence that describes the whole relationship.
I can say how big the ordinary scatter is, and which time sits far outside it.

You need

for each group: string with a metal washer or a lump of modelling clay tied to one end, sticky tape to fix the other end to the edge of a desk, a ruler and a stopwatch; a table on the board with a column for each length: 20, 40, 60 and 80 cm,
the relationship sheet (scaffold 1), one per student, and the cards from scaffold 3, one set per table.

Lesson flow (about 30 minutes)

5 min	Point by point Show the board (see the box). Ask: “After two points the description was simple. What did the later points change?”
10 min	Time and pool Groups time ten swings at each of the four lengths and write their times in the board table. Ask: “The times at 40 cm differ a little between groups. Is that a problem?”
10 min	Describe and question Students describe the relationship on the board data, then find any time far outside the spread of the others. Ask: “What could make one group’s time about half the others? What should we do with it?”
5 min	Sort the cards Tables sort the cards under the three heading cards. Ask: “Card C reads a pattern into three counts. How big would the change need to be to mean something?”

Running it shorter? Stop after the description, and look for the anomaly and sort the cards in your next science lesson.

On the board

For a worked example, open the unit and add the readings one at a time in “Watch the cooling trend take shape, point by point”. Then click the point in “Find the rate that breaks the trend”.

seegongsik.com/au/y8/inquiry/AC9S8I05

Watch for these ideas

Calling every small difference between groups an anomaly.
Deleting a time because it does not fit, instead of checking it.
Describing only the direction (“longer is slower”) and not the shape or size.

Make it easier, make it bigger

Easier: give the frame “As the length rose from 20 to 80 cm, the time for ten swings ... by about ..., and each 20 cm added ...”.
Bigger: predict the time for a 1 m pendulum from the pattern, then test it and say whether the description held.

Answers and look-fors

The next sheet has both relationship descriptions, the chalk differences and decision, the card key and a quick three-level guide. Typical times for ten swings: about 9 s at 20 cm, 13 s at 40 cm, 15.5 s at 60 cm and 18 s at 80 cm: rising, but each 20 cm adds less. A group that counted five swings will show about half.

Answers · For the teacherModel responses

Answers and look-fors

Relationship sheet

A. Falls of 24, 18, 12, 8, 5, 3 beats/min: “As the time after exercise rose from 0 to 6 minutes, the heart rate fell from 152 to 82 beats/min, quickly at first (by 24 in the first minute) and then more and more slowly, levelling off towards a resting rate.”

B. Steps of 1.3, 1.1, 1.2, 0.3, 0.1 °C: “Up to 4 g, the drop grew by about 1.2 °C for each gram; after that it stayed near 5.2 °C.” The vinegar is used up by about 3.5 g of powder, so extra powder has nothing left to react with.

Noise or anomaly?

Time (min)	0	2	4	6	8	10	12
Line predicts (g)	0.0	1.0	2.0	3.0	4.0	5.0	6.0
Difference (g)	0.0	-0.1	+0.1	-0.1	+1.6	0.0	+0.1

The ordinary readings sit within 0.1 g of the line: that is the noise. At 8 minutes the reading is 5.6 g, 1.6 g above the line, far outside it. Likely causes: a piece chipped or broke off, or the chalk was still wet from the jar and a crumb was lost as it was dried. Keep it, mark it, note the likely cause and shake and weigh at 8 minutes again. The trend stays about 0.5 g each minute, because the readings either side of it carry on along the line.

Description cards

Card	Statement	Pile	Why
A	As the shaking time rose from 0 to 12 minutes, the mass lost rose by about 0.5 g every minute.	Sound description	Direction, size and range, as the data shows.
B	Repeat readings of 29.8, 29.3 and 30.4 °C show the salt warms the water differently each day.	Reads noise as a pattern	A spread of about 1 °C between repeats is ordinary scatter.
C	The 30-second pulse counts went 36, 35, 37, so the heart sped up on the third count.	Reads noise as a pattern	One beat either way is counting wobble.
D	The temperature drop will keep growing by about 1.2 °C for every extra gram, even with 50 g of powder.	Reaches too far	The data levels off after 4 g, once the vinegar is used up.
E	In the data set, earthquakes were far more common within 100 km of a plate boundary than further away.	Sound description	A clear difference, kept to the data set.
F	Heart rate fell quickly in the first two minutes after exercise, then more and more slowly.	Sound description	Names the shape: a curve that flattens.
G	The bounce from 60 cm was 1 mm lower than the line, so balls bounce worse from 60 cm.	Reads noise as a pattern	A millimetre is smaller than the reading error.
H	Our granite samples were 2.7 g per cubic centimetre, so every rock on Earth has this density.	Reaches too far	Five granite samples say nothing about other rocks.
I	The temperature drop grew steadily up to 4 g of powder, then stayed near 5 °C.	Sound description	Describes both parts of the pattern.
J	Ice cream sales and sunburn cases rise together, so ice cream causes sunburn.	Reaches too far	Both rise with sunny weather; rising together does not show a cause.
K	The mass lost at 6 minutes was 0.1 g under the line, so shaking must slow down after 4 minutes.	Reads noise as a pattern	A 0.1 g gap is the size of the scatter; the later readings carry on.
L	Across the five granite samples, mass rose in step with volume, about 2.7 g for every cubic centimetre.	Sound description	A relationship with its rate, within the samples.

A quick three-level guide

Move	Working towards	At standard	Beyond
Describe the relationship	gives the direction only	gives direction, shape, size and range, and where the pattern changes	explains why the pattern changes where it does
Tell noise from an anomaly	calls any difference an anomaly, or none	sets the size of the scatter and finds the reading far outside it	suggests likely causes and how to remeasure
Keep the claim inside the data	claims a cause or stretches the pattern	keeps the description to the range and what was measured	says what further data would test a wider claim

A student at standard describes a relationship in full, separates noise from an anomaly by its distance from the trend, and keeps the claim inside the data. The skill grows all year, so keep the scaffolds coming back whenever results come in.