The internal assessment task will be one scientific investigation taking about 10 hours and the write- up should be about 6 to 12 pages long. Investigations exceeding this length will be penalized in the communications criterion as lacking in conciseness.
The practical investigation, with generic criteria, will allow a wide range of practical activities satisfying the varying needs of biology, chemistry and physics. The investigation addresses many of the learner profile attributes well. See section on “Approaches to the teaching and learning of physics” for further links.
The task produced should be complex and commensurate with the level of the course. It should require a purposeful research question and the scientific rationale for it. The marked exemplar material in the teacher support materials will demonstrate that the assessment will be rigorous and of the same standard as the assessment in the previous courses.
Some of the possible tasks include:
• a hands-on laboratory investigation
• using a spreadsheet for analysis and modelling
• extracting data from a database and analysing it graphically
• producing a hybrid of spreadsheet/database work with a traditional hands-on investigation
• using a simulation, provided it is interactive and open-ended
Some task may consist of relevant and appropriate qualitative work combined with quantitative work.
The tasks include the traditional hands-on practical investigations as in the previous course. The depth of treatment required for hands-on practical investigations is unchanged from the previous internal assessment and will be shown in detail in the teacher support materials. In addition, detailed assessment of specific aspects of hands-on practical work will be assessed in the written papers as detailed in the relevant topic(s) in the “Syllabus content” section of the guide.
The task will have the same assessment criteria for SL and HL. The five assessment criteria are personal engagement, exploration, analysis, evaluation and communication.

https://ibphysics2016.wikispaces.com/file/view/Physics_Guide_2016.pdf/487462852/Physics_Guide_2016.pdf

p.136 and after tells everything about the criteria.