Suggesting Improvements (Edexcel International A Level (IAL) Physics): Revision Note

Suggesting Improvements

• Improvements to an experiment help make it more reliable and reproducible to gain more trust in the results

• A common method is to use digital methods of data collection where possible

  • These subsequently reduce uncertainties that are a result of human error (e.g., reaction time)

Software & Tools

• Graph plotting and data analysis software, such as Microsoft Excel, can be an invaluable tool

  • Spreadsheets provide a very effective way of processing data, particularly when the amount of data is large

• Cameras can be used to take photos in experiments that happen too quickly to read a scale

  • A camera can be used to take a photo burst as the experiment happens

  • The scale can then be read from the photos afterwards

  • If the time each photo is taken is known, or if the frame rate is known, then properties such as velocity can be calculated

Data Loggers

• Data loggers are a tool that allows for the quick and efficient gathering of data

  • They are more accurate, quick and reliable than manual logging

• The information contained within a data logger can be inputted into a computer and formatted into a table

• After this is done the computer is able to calculate the average and plot graphs using the data and calculate gradients which quicker and more accurately than humans

• They are electronic devices that automatically monitor and record environmental parameters over time such as temperature, pressure, voltage or current

  • It contains multiple sensors to receive the information and a computer chip to store it

A data logger measuring and displaying temperature using a probe

• The benefits of using data loggers and ICT (information and communication technology) include:

  • Readings are taken with higher degrees of accuracy

  • Reduction of human error (e.g. human reaction times, subjectiveness)

  • Readings can be taken over a long period of time e.g. hourly readings of temperature over many days

  • Readings can be taken in a very short period of time, which would be too quick for humans to see a difference

  • Reduction in safety risks with extreme conditions such as measuring the temperature of boiling water

Computer Modelling

• Computer modelling is commonly done in conjunction with devices such as a data logger

  • Modelling is about processing the data collected from a physics experiment into software or a spreadsheet

• Graphs and charts can be generated from a table of values

  • These can then be exported to a scientific report

• One of the benefits of these computer programs is that time can be sped up to predict the future outcome of an experiment

Computer modelling uses a computer and sensors to analyse and display data

Making Methods Reproducible

• To improve upon an experimental method, it could be made more reproducible

  • This is the ability to be properly reproduced for other scientists to also see if they get the same results

•  For example, when measuring the resistivity of a wire, a constantan wire may be used

  • If the same method is used to measure an accurate value of the resistivity of copper or aluminium, then this means the method is properly reproducible 

• A further discussion of similarities and / or differences between the three wire materials can then be analysed 

• Another example could be when measuring the count rate of a gamma ray source

  • By using a more or less active source, more differentiation in their readings can be achieved