Types of delivery modes and issues to consider: 

Delivery Mode

• Personal Interviews: Gives respondent ability to taste, see, feel, etc. but is costly and may cause bias
• Phone:  Usually elicits longer and more detailed responses, but fewer people can be reached by home telephone
• Mail:  Inexpensive, but you need names and addresses and takes a lot of time
• Email:  Low cost and fast, but you need email addresses and response rate may be low

Important issues to consider:

• Speed: Email and web page surveys are the fastest methods, followed by telephone interviewing. Mail surveys are the slowest.
• Cost: Personal interviews are the most expensive followed by telephone and then mail. Email and web page surveys are the least expensive for large samples.
• Internet Usage: Web page and email surveys offer significant advantages, but you may not be able to generalize their results to the population as a whole.
• Literacy Levels: Illiterate adn less-educated people rarely respond to mail surveys.
• Sensitive Questions: People are more likely to answer sensitive questions when interviewed directly by a computer in one form or another.
• Video, Sound, Graphics: A need to get reactions to video, music, or a picture, limits your options.  You can play a video on a web page, in a computer-direct interview, or in person. You can play music when using these methods or over a telephone. You can show pictures in those first methods and in a m ail survey.