Skip to main content

Experimental Design

Division: Div B – Middle School

NC Essential Standards Alignment: Science as Inquiry

Event Rules: See the National Rules Manual

National Event Page: Here


This event will determine the participant’s ability to design, conduct and report the findings of an experiment entirely on site.


Participants must bring goggles and writing utensils.  Teams may bring one timepiece, one linear measuring device, and one stand along non programmable non graphing calculator.  Teams cannot use any of these are part of the experiment – they must only be used for their intended function.  The Event Leader will provide each team with identical sets of materials either at a distribution center or in an individual container.  The Event Leader must provide the 2-part reporting packet posted on the event page at for teams to record their experimental information and data.  


High score wins. Scoring will be done using the Experimental Design Checklist found on 

Common Mistakes:

– A statement of problem should never have a yes or no answer!

– Be careful not to confuse the different variable types (controlled, dependent, independent) .

  • A constant is unchanging. A controlled variable could serve as an independent variable in a different experiment but you are keeping it the same throughout your experiment.


– The more detail you give in your answer the better your score will be. For example, if asked to write a purpose question for a given scenario that had to do with types of napkins and different liquids:
“Which napkin is most absorbent?” received 1 out of 4 points.
Examples of 4 point answers are”What is the effect of the brand of napkin on it’s absorbency, determined by measuring how far (cm) water will diffuse up?” and “How does the volume of liquid absorbed by a napkin affect the amount of water retained as indicated by mass?”

In the same scenario, when asked for a hypothesis:
“If the napkin is thicker, then the napkin will be the most absorbent” received 2 out of 5 points.
Examples of 5 point answers: “If the overall density (g/cm3) of a napkin is increased then the absorbency will be higher as seen from the distance (cm) the water diffuses because a denser napkin will be able to contain more water within it’s fibers” and “If the liquid has a higher sugar concentration, then the napkin will have a higher absorbency, meaning that the diameter of the liquid stain on the napkin will be greater. This is because the greater the concentration of sugar molecules, the more difficult it is to permeate through the napkin”

While all of the answers given are correct, for higher scores teams need a more complete thought, which means more detail about what they are truly testing or looking for in a section – what is it about the napkin that makes them different- brand? density? porosity? thickness? material? pattern? color? shape? And how are they testing that element (in their case, absorption) – through density, mass, diffusion, etc.

Event Resources:

Experimental Design 2018 Coaches Clinic Presentation (2019 Rules)

Great Explanation with examples of the Scientific Method – Science Buddies