Goofs

In the scene (from 04:32 to 05:55 on the DVD) where Noah Wilder is in his bedroom, wearing pajamas and playing a video game, his father comes home late and visits with him. In one shot when Noah throws his video game controller down, you can see he is bare-foot. In the very next shot from a different angle, as his father is talking to him, Noah is wearing slippers. (Note: This is a "full-frame-only goof", not visible in the wide screen versions, because their frames were made by cropping 41.7% of the height of the spherical 35 mm film negative frames, cutting Noah's bare feet out of the frame, although his slippers can still be seen at 04:41. The full height of the negative is shown in the full frame version, leaving Noah's bare feet in their frames.) Also in this scene Noah's left leg is propped up when he is playing the video game but then when he is talking to his Dad it is his right leg that is propped up.

Early in the movie, the science teacher Larry White (Rainn Wilson) tells his class "of the doctors Watson and Crick who cracked the genetic code". This is wrong in two ways. First, while Watson and Crick's discovery of the double-helical structure of DNA helped explain how genes were replicated during cellular or viral reproduction, it was Marshall Nirenberg and Har Gobind Khorana who did the research that correctly interpreted the genetic code, for which they received the 1968 Nobel Prize in Physiology and/or Medicine (along with Robert W. Holley for his work on transfer RNA). Second, it is odd that Mr White refers to Watson and Crick as "doctors", which his class would understand to mean that they were medical men, which neither was; in fact while Watson had his PhD at the time of their seminal research, Crick had yet to complete his and held only a BSc - in physics.

In the original "Jabberwocky" poem by Lewis Carrol, "Mimzy" is an adjective, not a noun.

At approximately 52 minutes into the film, as the Wilder family is eating breakfast, during shots of Jo Wilder (Joely Richardson) a member of the crew can be seen reflected in the window behind her.

When the Wilders are going to Whidbey Island from Seattle the ferry is shown leaving downtown Seattle (at 06:30 on the DVD) where the only destinations are west going to Bremerton or Bainbridge Island. To take a ferry to Whidbey Island you need to drive 20 miles north to leave from Mukilteo. There is also a ferry from Port Townsend to Whidbey, but to take it the Wilders would have to take the Bainbridge Island ferry 7 miles, drive north 50 miles to Port Townsend, and take that ferry 5 miles east to Whidbey.

(at around 57 mins) The film takes place entirely in Seattle, but in one of the early scenes, they show a closeup of Noah's cellphone with a Bell Canada logo clearly visible on it.