Explain unambiguously how to look up a phone number in a phone book given the person's name. Also describe how to look up a person's name in the phone book given their phone number.

Adan

Answered a different question (the one posted on the outline as opposed to the one given in class).

Cathy

To look up a phone number:

1. Go to the section of the phone book that lists names starting with the same letter as the name you are using.

2. Find the part of this section that lists names with the same second letter as the name you are using.

3. Continue matching up each subsequent letter until there are no more letters left and you have found a match.

4. If you have found a name which matches the one you were looking for exactly, the number attached to it may be the one you are looking for.

To look up a name:

1. Find a reverse directory.

2. Go to the section of the phone book that lists numbers starting with the same number as the one you are using.

3. Find the part of this section that lists numbers with the same second number as the one you are using.

4. Continue matching up each subsequent number until there are no more numbers left and you have found a match.

5. If you have found a number which matches the one you were looking for exactly, the name attached to it is the one you are looking for.

(Note: there are easier ways to do these -- i.e. call information, type the name/number into certain web sites, or "*69" -- but I assumed that this was what you were looking for.)

Ivy

Ho to look up a phone # by name in the phone book. (assuming the person can distinguish between first and last names and knows the alphabet)

• 1) locate the first letter of the last name.
• 2) find the corresponding section in the phone book.
• 3) locate the second letter of the last name.
• 4) find the corresponding section in the phone book.
• 5) locate the next letter in the last name.
• 6) repeat steps 5 and then 4 until the last name has been located.
• 7) if there is more than one entry for the last name, determine the first name.
• 8) locate the first letter of the first name and see if there are any matches within the entries for the last name.
• 9) if there is more than one match, locate the next letter in the first name, match it to listed entries. proceed until there is only one match.
• 10) the number will be listed in the same row as the name, usually in the column to the right.

How to look up a name by a phone #. (as far as i know, there is no efficient way to do this using a physical phone book)

• 1) open the phone book. start at the first listing for numbers.
• 2) scan through all numbers, going down column by column until you have found a match.
• 3) good

Jae

Algorithm for finding a number for a name in a phone book:

• 1. Remember the name, last name first, first name last, and the appropriate spelling.
• 2. Using the first letter of the last name, locate the appropriate alphabetical section in which the name should appear.
• 3. Using the second letter of the last name, find the subsection of first and second letters combined, in the appropriate order, in which the name should appear. (If the last name consists of only two letters, find the appropriate first name.)
• 4. Using the third letter, find the possible names in a subsection of the first three letters in the correct order. Continue this step with x+1 letters of the name until you have a subsection of names exactly matching the last name of the person whose number you are trying to locate. (x is the number of letters used in the previous step, consistently.) If there is only one of the last name, (check for duplicates) identify the number, and return phone number information.
• 5. Begin the second step using the first letter of the first name, but limit the section to only those exactly matching the last name. Continue to step 4, again focusing on the first name only within the set of exactly matching last names.
• 6. When both first and last name match the name you are locating, check for duplicates. IF there are no duplicates, return phone number information.

Algorithm for finding a name from a number in a phone book:

• 1. Identify and remember the number for the name you want to find. Remember the area marker at the beginning of a phone number and the four digits separately.
• 2. Begin checking in the front page of listed numbers in the phone book. If the area marker matches, then and only then [check for the remaining four digits in correct order.]
  • A. Only looking at those numbers with the correct area marker, check for the first digit in the four.
  • B. Each time you find a first digit match, check for the second digit match. If it does not match, return to A beginning with the next number on the list.
  • C. If it does match, check for the third digit match. If it does not match, return to A beginning with the next number on the list.
  • D. If it does match, check for the fourth digit match. If it does not match, return to A beginning with the next number on the list.
  • E. IF it does match, return the name information for the located number, and stop.

Jeana

Assuming you know what alphabetical order means, given a phone book and a person's name:

• 1. Alphabetically look up the person's last name in the phone book.
• 2. Once you've looked up the person's last name, locate the person's first name alphabetically within that listing of last names (e.g. if the person's last name is willis, look alphabetically within the 'willis' listings for their first name).
• 3. Once you've located their full name, follow the dotted line straight across to the right to locate the phone number.

Given a phone book, a phone number and no name: I don't know that there's any way to realistically locate the person to whom the number belongs. Essentially, to find it's owner, you'd have to just start scanning down the phone numbers until you found a match. Hugely inefficient and time-consuming, and that's assuming the number is even listed.

Jeff

Given a name describe how to determine a telephone number

• 1.) Identify first letter in name
• 2.) Turn to the page(s) of the identified letter in the phone book.
• 3.) The section of the phone book which contains the identified letter as the first letter now comprises the entire domain in which future searches will occur
• 4.) Identify the second letter in the name
• 5.) Repeat step two
• 6.) The section of the phone book which contains the first identified letter first and the second identified letter second now comprises the entire domain in which future searches will occur

• 1.) Identify the n1 (first letter) letter in the name
• 2.) Turn to page(s) of the identified letter in the phone book
• 3.) The section of the phone book which contains n1 now comprises the entire domain in which future searches will occur
• 4.) If there are remaining letters, then continue process for letter n(x+1) where x the number of previous searches

Given a phone number describe how to determine a name

• 1.) Begin at the beginning of the phone book
• 2.) Locate next number which has not been previously compared
• 3.) If known number does not match number, then locate next number and begin at step two or if known number does match number, then return name of matching number

Joel

Describe the how to put names and corresponding phone numbers in a phone book alphebetically.

• 1. Enter everyone's name (last name first) along with their corresponding phone number.
• 2. Somehow make sure that each person's phone number stays attached to the correct name at all times, no matter where it is moved to (I'm not sure how to do that).
• 3. Assign the first letter through the last letter in each person's full name (last name first) to a corresponding number (e.g. A = 1, B = 2, ...).
• 4. Put the numbers (i.e. the letters) in order from smallest to greatest, starting with the first letter in the person's last name and going to the last letter in the person's first name.
• 5. If two numbers are the same for first letter, then you need to go to the next letter, and continue until the numbers (letters) are different.
• 6. Continue this process until all the numbers are in order from smallest to largest, and therefore, putting the names (and phone numbers) in alphabetical order.

Kevin

1. People's names are generally arranged in phone books in alphabetical order by the last name of the person. The first name of the person is listed after the last name so that people of the same last name can be differentiated. Arrange the name in question in that manner, with the last name first and the first name last.

2. Phone books have index names at the top of each page to make the identifying of one name easier. Go to the first page with indices which have the same first letter of the last name as that of the name in question.

3. Within the range of this first letter, go to the first page with the second letter of the subject's last name. Continue doing this with each successive letter of the person's name, until you have arrived at a name identical to that of the one for which you are searching.

4. Write down the number associated with the name you have found.

5. In the event of multiple people with the same name, it may be necessary to call each of the multiple numbers to discover which is the person for whom you are searching.

With the number.

1. Phone books are NOT put in numerical order by phone number.

2. Write down your number so that it is easy to compare (and hard to forget) when comparing.

3. Beginning with the first page of phone listings, compare every number in the phone book with that you have written until a number is found which is an identical match.

4. Write down the name of the person with whom the number is associated.

5. Multiple people should not have the same number.

Liz

To find number g given name x:

• 1.For each listing (name, phone number) in the book,
  • if x=name, return phone number.
  • otherwise, discard name and repeat step 1.

To find name x given number g:

• 1. For each listing (name, phone number) in the book,
  • if g=phone number, return name.
  • otherwise, discard phone number and repeat step 1.

Sam

How to look up a phone number if you have a name:

Since this is the purpose for which a phone book is designed, this task is not extremely difficult.

• 1. Accquire a phonebook for the area where the designated number's owner resides. Use the "White Pages" section, as this is the residential section and is organized alphabetically.
• 2. Using the persons last name, locate the section of the phone book that alphabetically correspnds (i.e. if their name is Smith, turn to the S section)
• 3. Locate their last name in the book, first by the first letter, then using the ensuing letters to narrow the search down (Smith> Sm-, Smi-, etc).
• 4. If there are repeat last names, consult their first name to narrow the search. If there are repeat first names, consult their middle initial then address.
• 5. If the name you have singled out is in accordance to the address you have, and if the right person picks up the phone when you call, you have successfully used a phone book.

How to look up a name if you have a number: A decidedly harder process, considering that this is not the intended way of using a phonebook.

• 1. This is going to be a length process of elimination. First narrow the search as much as initially possible. Using the area code (the first 3 digits) determine the general location of the owner of the number. Get the appropriate phone book.
• 2. Note the first digit in the local number (the last 7 digits). Going through the book page by page, highlight all of the numbers that share this digit. Eliminate the rest.
• 3. Note the second digit of the number and repeat step two, eliminating the phone numbers that do not have the designated second digit.
• 4. Continue this process, going digit by digit, until the matching numbe remains. the number has now been located.

...or maybe try starting with the last digit and working backwards. The first one or two digits are more likely to be shared, so they are more easily eliminated later.