Each skill has a mastery level between 0 and 100. Getting to different thresholds will achieve 1, 2 or 3 bars of mastery at that skill.
Each skill consists of subskills (mostly Key Skills) of varying difficulties. To get to higher mastery at a skill, you not only need to get questions consistently correct; you need to also master subskills of higher difficulty. Suppose the difficulty within a skill varied from 1 to 4. You could get up to a mastery of 25/100 by answering difficulty 1 question, 50/100 by answering difficulty 2, and so on.
The mastery level also allows us to determine the most appropriate questions to choose for you/students when you select multiple subskills or when you practice/set a task on a skill as a whole.
Key Skills vs Exam Practice
There's two sources of questions. Exam Practice ('E' numbers) involves past paper exam questions from a variety of exam boards. Key Skills ('K' numbers) generate random questions on more specific question types, and are accompanied by shorter worked example videos.
We recommend using Key Skills to master specific concepts and question types, and using Exam Practice for a broader range of questions within a topic.
Select topics using the tree, then select a mixture of whole skills or the subskills within them.