designing algorithms to solve real-world problems and describing algorithms using flow charts and structured English, for example START, END, IF and UNTIL
recognising that different algorithms can solve a problem with different trade-offs
tracing algorithms to predict results and program state for a given input, for example desk checking or using an interactive debugging tool
using tracing techniques to test algorithms, for example desk checking an algorithm for a given input by stepping through the algorithm while keeping track of contents of the variables
developing test cases that correspond to the requirements of the specifications, for example validating program behaviour on a range of valid and invalid user input