What is it?

The Morris Water Maze is basically a pool of water that animals are placed into.

What is it supposed to measure? 

This "maze" is supposed to help study spatial memory and learning.

How does it work? 

An animal is placed into a pool of water that is often colored so the animal cannot see a hidden platform, nor can they rely on scent to find the platform because the colored water is often opaque with powered non-fat milk or non-toxic tempera paint.

What does a rodent do within this paradigm (or what happens to the rodent)? 

The rodent is supposed to try and find an escape route, being the hidden platform, solely by relying on external/extra-maze cues. Once the rodent figures out the escape route, as it is placed in the maze more and more, it should be able to more quickly find the platform than it was able to before.

What equipment do you need to run it?

To run this experiment, you would need a round pool, roughly 6 feet wide by 3 feet deep, filled with opaqued water, a video camera to record the rodents behaviors, and an escape platform.

 What else would you need to know to use it? 

The paper that I read mentioned that the water needs to be within 1 degree of 26 degrees Celsius and that you need to train the animal first in the water maze with the platform exposed above the clear water surface to let it get used to the water maze and to let it know that the platform is the escape route. This paper also mentioned that you should time how long it takes the rodent to get to the platform, and that if it doesn't get to the platform, do not pick it up, but instead guide it to the platform with your hand. This way, the rodent knows that in order to be "rescued" from the water maze, it must be on the platform.

What are your thoughts, if any, on the validity of this method?

I believe this to be a valid method, as it does test the memory of the rodent in terms of remembering that it needs to find the platform to be rescued from the pool. The opaque water also forces the rodent to learn external cues and not rely on its sense of vision or smell, as those are useless in these kinds of experiments. It definately tests how quickly a rodent can learn other strategies to solve issues, as well as tests how good the memory of the rodent is, as they needs to learn and remember how they can and did reach the platform during the training trials.

 What concerns, if any, would you have using it as a measure?

The only main concern I would have using this experiment would be that the rodent or other animal in the pool may drown, especially if the pool is three feet deep and if they got tired because they couldn't find the platform.

Can you think of any other problems or improvements?

I can't think of any other problems, as the paper said if the rodent was getting tired or appeared to be struggling for longer than a minute, to take you hand and guide the rodent to the platform, that way you're also reinforcing that the rodent must be on the platform to be saved, which also tests and forces the formation of learning and memory, while ensuring the safety of the animal, which is what this experimental method form is all about.