Are the results of this experiment valid? 

 Write at least 2 sentences saying why or why not.
I plant a garden and notice that some of the plants are not growing.
I wonder why some plants are growing and others are not.
I think that if I plant my plants in the partial shade they will grow better than in the full sun.
I plant 5 sunflowers in the sun and 5 carnation plants in the shade. I make sure to water all the plants a couple of times a week.
I measure all the plants each day for two weeks. 
At the end of two weeks I find that on average the plants in the sun grow 5 more inches than the plants in the shade.
I conclude that these plants grow better in the sun.