Addressing safety of self, others and the environment

• Recognize and address relevant safety, ethical or environmental issues in an investigation.

Measuring variables - Understand how to accurately measure the following to an appropriate level of precision.

• Mass
• Volume
• Time
• Temperature
• Length
• pH of a solution
• Electric current
• Electric potential difference

Applying techniques - Show awareness of the purpose and practice of:

• preparing a standard solution
• carrying out dilutions
• drying to constant mass
• distillation and reflux
• paper or thin layer chromatography
• separation of mixtures
• calorimetry
• acid–base and redox titration
• electrochemical cells
• colorimetry or spectrophotometry
• physical and digital molecular modelling
• recrystallization
• melting point determination

Applying technology to collect data

• Use sensors
• Identify and extract data from databases
• Generate data from models and simulations

Applying technology to process data

• Use spreadsheets to manipulate data
• Represent data in a graphical form
• Use computer modelling

Applying general mathematics

• Use basic arithmetic and algebraic calculations to solve problems
• Carry out calculations involving decimals, fractions, percentages, ratios, reciprocals and exponents
• Carry out calculations involving logarithmic functions
• Carry out calculations involving exponential functions (additional higher level)
• Determine rates of change from tabulated data
• Calculate mean and range
• Use and interpret scientific notation (e.g. 3.5 × 10⁶)
• Use approximation and estimation
• Appreciate when some effects can be ignored and why this is useful
• Compare and quote values to the nearest order of magnitude
• Understand direct and inverse proportionality, as well as positive and negative correlations between variables
• Calculate and interpret percentage change and percentage difference
• Calculate and interpret percentage error and percentage uncertainty
• Distinguish between continuous and discrete variables

Using units, symbols and numerical values

• Apply and use International System of Units (SI) prefixes and units
• Identify and use symbols stated in the guide and the data booklet
• Express quantities and uncertainties to an appropriate number of significant figures or decimal places

Processing uncertainties

• Understand the significance of uncertainties in raw and processed data
• Record uncertainties in measurements as a range (±) to an appropriate level of precision
• Propagate uncertainties in processed data, in calculations involving addition, subtraction, multiplication, division and (HL only) exponents
• Express measurement and processed uncertainties—absolute, fractional (relative), percentage—to an appropriate number of significant figures or level of precision
• Apply the coefficient of determination (R2) to evaluate the fit of a trend line or curve

Graphing

• Sketch graphs, with labelled but unscaled axes, to qualitatively describe trends
• Construct and interpret tables, charts and graphs for raw and processed data including bar charts, histograms, scatter graphs and line and curve graphs
• Plot linear and non-linear graphs showing the relationship between two variables with appropriate scales and axes
• Draw lines or curves of best fit
• Interpret features of graphs including gradient, changes in gradient, intercepts, maxima and minima, and areas
• Draw and interpret uncertainty bars
• Extrapolate and interpolate graphs

Exploring

• Demonstrate independent thinking, initiative, and insight
• Consult a variety of sources
• Select sufficient and relevant sources of information
• Formulate research questions and hypotheses
• State and explain predictions using scientific understanding

Designing

• Demonstrate creativity in the designing, implementation and presentation of the investigation
• Develop investigations that involve hands-on laboratory experiments, databases, simulations, modelling
• Identify and justify the choice of dependent, independent and control variables
• Justify the range and quantity of measurements
• Design and explain a valid methodology
• Pilot methodologies

Controlling variables - Appreciate when and how to:

• calibrate measuring apparatus
• maintain constant environmental conditions of systems
• insulate against heat loss or gain

Collecting data

• Identify and record relevant qualitative observations
• Collect and record sufficient relevant quantitative data
• Identify and address issues that arise during data collection

Processing data

• Carry out relevant and accurate data processing

Interpreting results

• Interpret qualitative and quantitative data
• Interpret diagrams, graphs and charts
• Identify, describe and explain patterns, trends and relationships
• Identify and justify the removal or inclusion of outliers in data (no mathematical processing is required)
• Assess accuracy, precision, reliability and validity

Concluding

• Interpret processed data and analysis to draw and justify conclusions
• Compare the outcomes of an investigation to the accepted scientific context
• Relate the outcomes of an investigation to the stated research question or hypothesis
• Discuss the impact of uncertainties on the conclusions

Evaluating

• Evaluate hypotheses.
• Identify and discuss sources and impacts of random and systematic errors
• Evaluate the implications of methodological weaknesses, limitations and assumptions on conclusions
• Explain realistic and relevant improvements to an investigation