How many times a month do you eat pizza?
--The answers categorized participants into Males & Females and NW, Midwest, South, West). Nowhere did Zagat or HuffPost define the state/boundaries, which is necessary when grouping and generalizing the participants.
Pizza consumption during what meal?
--Dinner, Lunch, Late Night Snack, Breakfast. 'Late night' should just be written as 'Snack' because many people eat multiple small meals throughout the day, or add 'Midday snack' as an option.
They gave a list of the 9 pizza type favorites, 10 favorite toppings, 5 of the grossest, and 5 favorite fixins. With so many brands, and the fact that some pizzas (Chicago deep-dish, NY-style thin crust, etc.) are specific to a certain region or city influence participants. NY is known for pizza. Chances are Minnesota's 'NY-style' is different than the native.
Which are the grossest [toppings]?
--Were people given a list of toppings to choose from or was it an open-ended question?
Is it better to order by the pie or a slice?
--What exactly does 'better' imply? This question is ambiguous and not clear enough to a participant. People order by the pie if they are looking to save money and will save the leftovers, they may be hosting a party, they may be feeding an entire family one meal, etc. The answer is situational and the question does not address that, creating a lack of control.
How much did you spend on a slice? On a pie?
--Were participants given money by Zagat to buy and eat pizza from certain place? Or were the participants just giving prices that seemed logical. It is unlikely that pizza consumers remember the price of their food, down to the cent.
As a journalist, I would also like to know if any pizza companies were involved in the research process, which could sway the participants, the survey method(s), and researchers perhaps looking for certain answers. How the study was funded is an important factor, as is location, method, and approach to participants.
It is also not stated the sample size. Most answers are presented as percentages, which has little reliability until we know if the sample size was large enough and a well-representation of opinion. The sample size could have been 5,000 people across the nation or it could have been 100. It is important in this study to know how many people were surveyed, where, and their ages because urban, suburban, and rural areas are different pizza-wise. The attitude towards pizza varies among generations, as well. It is most likely younger people/students without time to cook or bake a pizza on his/her own. They could also be parents or someone hosting guests. Also, 'Late night snack' as an option to a question applies mostly to youth that stay up late studying or stop for pizza after bar close.