Principles of Good Interface and Screen Design 249

Step 3: Principles of Good Interface and Screen Design 249

Not understanding the user. With so much variation among users there can never

be a single ideal search interface. Too often, however, the level of searching exper- tise of the user is not determined. The nature of every possible query or the type of information being searched for is not anticipated. Not considered, as well, are some basic human traits. Few people read instructions, preferring to “try it.” Instructions may not even be seen or may be simply ignored. People do not remember things very well. The existence of a search engine on another page, and/or the page’s location is easily forgotten.

Difficulties in formulating the search. One study found that the average Web shopper does not know how to use a search function. Another study found that the users did not know what to type in or how to format the query. These prob- lems can occur because of the diversity in user search needs. They may also occur due to numerous interface differences that create inconsistencies in layout and operation. Finally, too often the user is asked to think like the programming behind the search engine, a fruitless task. If the wrong search parameters are cho- sen, no results will appear.

Many users make many mistakes. People make mistakes in spelling. Fowler and Stanwick (2004) report a study carried out by the British Broadcasting System on users of the search engine BBCi Search. One in 12 search terms were misspelled, translating into over 30,000 search queries with misspellings on a particular day. Lots of people misspell words; 3 percent of all queries in another study contained misspellings, most off by only one letter. Misspelling may be caused by unfamil- iarity with technical terms or the English language, by spelling difficulties, or simply by one’s finger straying in the keying process. If the search engine does not accept misspelled variations, the chance of a search success is very slim.

Overly literal search engines. Overly literal search engines cannot handle typing mistakes, plurals, hyphens, and other variants of query terms (Nielsen, 2004).

Page titles with low search engine visibility.

A page title is the food for a search engine in formulating a search response. Irrelevant titles may not be captured. Titles that are not descriptive or clear may not be understood as relevant by the user. Page titles should begin with descriptive information-carrying words that tell the user exactly what will be found on a page (Nielsen, 2004).

Difficulties in presenting meaningful results. Users are often frustrated with pre- sented results because they do not know what the results mean, why they were presented, or what their relevance is to their query. If the chosen search parame- ters are too narrowly defined, no results or irrelevant results may appear. If too broadly defined, the user is inundated with results and the right answer is buried within. The user must then sift through all the useless data to try and determine where to go. Users often cannot tell that a “No Matches Found” result occurred because of a simple keying typographical error. The wrong key was pressed. Result descriptions consisting of a few words often make no sense, as do URLs displayed in the results for novice users. Displayed search accuracy ratings are seldom relevant to any one particular user. Goal-oriented users don’t care how rel- evant results are for someone else; their only concern is the information they need.

250 Part 2: The User Interface Design Process