Lesson 6: Data Processing, Averaging & Scientific Graphing

NCEA Level 1 Science. Students calculate reliable means, identify and exclude anomalous data points, plot scientific line graphs, and write Logbook Section 6.

Lesson at a Glance | He Tirohanga Whakamua

Do NowWhat is an anomaly and when do you discard it?10 min
Calculating MeansProcess raw data into reliable averages (1 decimal place)15 min
SALT Graphing RuleScale, Axes, Labels (+units), Title15 min
Logbook EntryWrite Section 6: Processed Data Table & Graph10 min
Exit VerificationConfirm graph includes units on both axes5 min

Ngā Whāinga Ako | Learning Intentions

Students will know

  • How to calculate reliable mean averages for each IV condition from raw trial data.
  • How to spot an anomalous outlier (e.g. 14, 15, 3) and justify excluding it from mean calculations.
  • The standard conventions for graphing continuous scientific data in Level 1 Science (SALT acronym: Scale, Axes, Labels + Units, Title).

Students will demonstrate

  • By calculating processed means for all 5 IV conditions and plotting a scientific scatter/line graph.
  • By completing Section 6 of their Level 1 Science Biological Investigation Logbook.

Curriculum alignment

  • NZC (2007) · Science · Level 6 · Nature of Science: “Apply their understandings of science to evaluate both popular and scientific texts (including visual and numerical literacy).”
  • NZC (2007) · Science · Level 6 · Nature of Science: “Use a wider range of science vocabulary, symbols, and conventions.”

Do Now | Tīmatanga Whakaaro (10 min)

Data Processing Prompt:

"Trial 1: 12 bubbles, Trial 2: 13 bubbles, Trial 3: 2 bubbles. What is the mean, and why is calculating (12+13+2)/3 = 9.0 incorrect science?"

Unpack: 2 is far from the other two readings, so it may be an anomaly — but you need a stated rule before excluding anything: a procedural fault recorded at the time (an air pocket, a timer error), or a reading outside an agreed range of the others. If the rule is met, cross it out, state the reason, and calculate the mean of the remaining trials: (12+13)/2 = 12.5 bubbles. If it is not, keep the reading, report the mean of 9.0, and repeat the trial.

The SALT Rule for NCEA Scientific Graphing (15 min)

📏 S — Scale

Equal intervals covering at least 50% of the graph grid. Do not use awkward scale multipliers (e.g. 3, 7, 9).

📈 A — Axes

Independent Variable on X-axis (horizontal). Dependent Variable mean on Y-axis (vertical).

🏷️ L — Labels & Units

Clear text labels on both axes with exact measurement units in parentheses (e.g. Distance from Lamp (cm)).

📌 T — Title

Descriptive title stating the relationship: "The effect of [IV] on the mean [DV] in [Organism]".

📁 Biological Investigation Logbook — Section 6: Processed Data & Graph

Students open their Level 1 Science Logbook and complete Section 6:

Section 6 Requirements:

1. Processed Data Table: Columns for IV level, Trial 1, Trial 2, Trial 3, Anomalies Excluded, and Calculated Mean (rounded to 1 decimal place).

2. Scientific Graph: Hand-drawn grid plot or digital chart following the SALT rule, with points accurately plotted and a line of best fit or point-to-point line.

3. Anomaly Statement: 1 sentence explaining any discarded outliers (or stating "No anomalies observed").

Exit Verification | Ka Mutu Hoki (5 min)

Exit Check:

"My Section 6 table contains calculated means for all 5 IV levels, and my graph includes full SALT labels ready for Lesson 7 conclusion writing."

Teacher Planning & NCEA Alignment

NCEA Level 1 Science Alignment:

  • Data Processing: Process and represent raw data in an appropriate format (table of means and scientific graph).
  • Graphing Conventions: Follow standard scientific graphing conventions (SALT rule, line of best fit / trend line).

Vocabulary: Processed mean, anomaly, outlier, SALT rule, scale, X-axis, Y-axis, trend line, data processing.

Other teaching approach: Guided Viewing & Practical Investigation →