Best Practices for Search

for the Federal Government

Marti HearstWeb Manager University

November 10, 2009

The Importance of Search for Govt

• OMB memorandum, Dec 2005:“When disseminating information to the public-at-large, publish your information directly to the internet.”

• Pres. Obama’s memorandum, Jan 21, 2009:“Information maintained by the Federal Government is a national asset. My Administration will take appropriate action, consistent with law and policy, to disclose information rapidly in forms that the public can readily find and use. ”

A bit about me• Professor at the School of Information

at University of California, Berkeley. Teach masters students User Interface Design, Search

Engines, Computational Linguistics, Visualization.

• Search User Interfaces• Visiting government for 1 year

Updating usasearch.gov Looking at site search alternatives. Generally kibbitzing

Two Focus Areas

• Web search engines The quality and form of your content How your results are viewed in

search engine listings How your site is crawled

• Site search The search interface What is crawled How results are presented

Outline

• Designing your site for effective search

• Site search interfaces• Special considerations for web

search engines• An example of what not to do.

• both content and tech people• have to be focused on it together

• mention why using (free) book example• add an exercise towards the start

• top 3 things to do right away• don’t force h1n1, be sure swine flu too• seo integrated into process

Use Proven Interface Techniques

Use modern search UI ideas that are known to have good usability.

Apply the principle: recognition over recall.• Related query suggestions• Auto-suggest as the user types• Use faceted navigation where appropriate.

Search-as-you-Type (SAYT)

• As the user types, shows other peoples’ queries with the same word stems.

• Helps people think of additional words (recognition over recall)

• Proven to improve search results.

Evidence-based Decision Making

DATA TRUMPS INTUITIONS (Kohavi)

Use Evidence-based Decision Making

User behavior determines if an idea is retained.

A/B testing is a standard way to do this.1) Make small changes to an interface.2) Show the changed interface to a

significant sample of the user population, show everyone else the original version.

3) Do this over time (~ two weeks) and for (tens of) thousands of users.

4) Compare what the two groups do over time.

5) Based on this, decide whether to keep or reject the feature.

Evidence-based Decision Making

• Example: Dan Siroker on Obama for

America’s website and video design decisions

Easy to measure the outcome: it is in money donated.

http://www.siroker.com/archives/2009/05/14/obama_lessons_learned_talk_at_google.html

Vote: Which Button is Best?

count down counter

Which Button is Best?

Which Button is Best?

Ease of Use: Summary

USE PROVEN UI TECHNIQUES

REDUCE EXTRA STEPS

USE CLEAR LANGUAGE

MAKE EVIDENCE-BASED UI DECISIONS

How Web Search Engines Work

How Search Engines Work

i. Gather the contents of all web pages (crawling)

ii. Organize the contents of the pages in a way that allows efficient retrieval (indexing)

iii. Take in a query, determine which pages match, and show the results (ranking and display of results)

Three main parts:

Standard Web Search Engine Architecture

userquery

Standard Web Search Engine Architecture

crawl theweb

Create an inverted

index

Check for duplicates,store the

documents

Inverted index

Search engine servers

DocIdsCrawlermachines

Standard Web Search Engine Architecture

crawl theweb

Create an inverted

index

Check for duplicates,store the

documents

Inverted index

Search engine servers

userquery

Show results To user

DocIdsCrawlermachines

i. Spiders or crawlers

• How to find web pages to visit and copy? Can start with a list of domain names,

visit the home pages there. Look at the hyperlink on the home

page, and follow those links to more pages.

Keep a list of urls visited, and those still to be visited.

Each time the program loads in a new HTML page, add the links in that page to the list to be crawled.

Spider behaviour varies

• Parts of a web page that are indexed

• How deeply a site is indexed • Types of files indexed• How frequently the site is

spidered

Four Laws of Crawling

• A Crawler must show identification

• A Crawler must obey the robots exclusion standardhttp://www.robotstxt.org/wc/norobots.html

• A Crawler must not hog resources

• A Crawler must report errors

Lots of tricky aspects• Servers are often down or slow• Hyperlinks can get the crawler into

cycles• Some websites have junk in the web

pages• Now many pages have dynamic

content• The web is HUGE

The Internet Is Enormous

Image from http://www.nature.com/nature/webmatters/tomog/tomfigs/fig1.html

“Freshness”

• Need to keep checking pages Pages change

• At different frequencies

• Pages are removed

Many search engines cache the pages (store a copy on their own servers)

What really gets crawled?

• A small fraction of the Web that search engines know about; no search engine is exhaustive

• Not the “live” Web, but the search engine’s index

• Not the “Deep Web”• Mostly HTML pages but other file

types too: PDF, Word, PPT, etc.

ii. Index (the database)

Record information about each page• List of words

In the title? How far down in the page? Was the word in boldface?

• URLs of pages pointing to this one• Anchor text on pages pointing to

this one

Inverted Index• How to store the words for fast lookup• Basic steps:

Make a “dictionary” of all the words in all of the web pages

For each word, list all the documents it occurs in.

Often omit very common words• “stop words”

Sometimes stem the words • (also called morphological analysis)• cats -> cat• running -> run

Inverted Index Example

Image from http://developer.apple.com/documentation/UserExperience/Conceptual/SearchKitConcepts/searchKit_basics/chapter_2_section_2.html

Inverted Index

• In reality, this index is HUGE• Need to store the contents

across many machines• Need to do optimization tricks to

make lookup fast.

Query Serving Architecture

• Index divided into segments each served by a node

• Each row of nodes replicated for query load

• Query integrator distributes query and merges results

• Front end creates a HTML page with the query results

Load Balancer

FE1

QI1

Node1,1 Node1,2 Node1,3 Node1,N

Node2,1 Node2,2 Node2,3 Node2,N

Node4,1 Node4,2 Node4,3 Node4,N

Node3,1 Node3,2 Node3,3 Node3,N

QI2 QI8

FE2 FE8

“travel”

“travel”

“travel”

“travel”

“travel”

…

…

…………

…

…

iii. Results ranking

• Search engine receives a query, then• Looks up the words in the index,

retrieves many documents, then• Rank orders the pages and extracts

“snippets” or summaries containing query words.

Most web search engines assume the user wants all of the words

• These are complex and highly guarded algorithms unique to each search engine.

Some ranking criteria • For a given candidate result page, use:

Number of matching query words in the page Proximity of matching words to one another Location of terms within the page Location of terms within tags e.g. <title>, <h1>,

link text, body text Anchor text on pages pointing to this one Frequency of terms on the page and in general Link analysis of which pages point to this one (Sometimes) Click-through analysis: how often the

page is clicked on How “fresh” is the page

• Complex formulae combine these together.

Measuring Importance of Linking

• PageRank Algorithm Idea: important pages are pointed

to by other important pages

Method:• Each link from one page to another is counted as

a “vote” for the destination page• But the importance of the starting page also

influences the importance of the destination page.• And those pages scores, in turn, depend on those

linking to them.

Image and explanation from http://www.economist.com/science/tq/displayStory.cfm?story_id=3172188

CRAFT SITES FOR FINDABILITY

(SEO)

Making Web Sites Attractive to Search

Engines• Called “Search Engine

Optimization” (SEO)• There is a LOT of information

about this on the web Most is about how to improve your

site Some is about “cheating”; avoid this

• There are many tools to help you too.

The Most Important Principle:

Good, unique content trumps everything else.

Content is Key

• Web sites that are primarily high-quality, unique content will be ranked highly. Not just links to other content Not re-packaging of other content

• Example: My online book was top ranked for “search

user interfaces” within one day of site launch.

It is also top ranked for many related queries.

Web Site Characteristics

• These can lead to high search engine ranking (but no guarantees): High-quality, unique content. Linked to by high-quality sites. Been around a long time with

consistent content.

Keyword Placement

• Search engines place “weight” on words according to where they are used

• Place important words in Title tags Headings (H1 is key) and emphasized

text Visible body text Description metadata – often used in

search results snippets. Alt text in images

Keyword Variation

• Describe the same concepts using different words within the relevant pages. Compare “search interfaces” with “search user

interfaces” in the next slide. 1 hit versus 4 hits in the top 6 I need to use more variation for the key concepts

• But it must make sense in your page; Don’t hide dictionaries of words ! Can include them in the description

metadata.

• put in aw-stat logs

The Importance of URLs

• Meaningful, short urls improve search engine ranking and usability

• Urls that consist of computer-generated database queries can hurt rankings.

• Urls with lots of redirects also hurt.

The Importance of Titles

• The title tag determines what words show up in the search results title. Make them descriptive of the site Vary them to differentiate them.

• Example (next page) Consistently varies the title to show

how they differ. But makes a mistake in the metadata

description by putting the part that varies too far from the start, so it all looks the same.

Robots Exclusion

• It is important to check your robots.txt files to be sure they are allowing crawling.

• If your server can’t handle a lot of traffic, use the site map file to slow crawlers down.

Site Maps

• There are two kinds of site maps:1. A navigation structure visible to

users2. An XML file visible only to

search engines• The latter is important to help ensure the

pages on your site are crawled.• You can also specify the frequency with which

you hope the pages will be crawled.• There are free tools to help you do this.

Examples of What Not To Do

For both site design and SEO.

Or … don’t mess with my dog!

Photo of Emmi

What happens when you search for recalls

?

What happens when you type

http://recalls.gov

?

The lesson: make your url (web address) easy

to find There should at least be a

redirect from recalls.gov to www.recalls.gov

Also, the url should match its description in the site title

field!

Where is search on this site?

The point: the search entry form should be highly visible and in a

standard position.

Usually wide and centered towards the top or else

shorter and on the upper right.

Where do I search for that recent dog food

recall?

The point: do not make the user guess how your information is

structured.There should be one search engine for all government recall

information.

The point: do not require users to fill out

structured search forms.

This can be an option but should not be required.

Showing categories with previews of how many hits are associate with each is better than lots of

entry forms.

What happens after I search?

The point: use standard layout

(unless there is a good reason not to)

This site puts too much text at the top before showing search

results.

Also, searchers frequently modify their query

It is standard to show the search form with the previous query at

the top.

The point: do promote commonly requested

information to the top of the results.

This site uses “best bets” to promote popular

content to the top; the user finds what they want.

What happens if I search for recalls at

searchusa.gov?

The point: use descriptive titles.

It is important to put the distinguishing information first so the repeated part does not

dominate. For example:

Home page: Recalls.govRecent Recalls

Food Safety RecallsAutomotive Recalls

What happens if I search for car recalls at major search engines?

What happens if I search for car recalls at major search engines?

Answer: I don’t see recalls.gov

What is on the page for car recalls?

The point: use words that your users use.

Notice that the main page for cars at recalls.gov does not appear

towards the top. The word “car” does not play an important role on

relevant page.

Tools for Improving Web Sites for Search Engines

Search Engine Information

• SEO http://www.ninebyblue.com/

• Keep current with industry http://www.searchengineland.com http://battellemedia.com

• Search Interface Principles http://searchuserinterfaces.com

• Search Design Patterns (Peter Morville) http://

www.flickr.com/photos/morville/collections/72157603785835882/

Faceted Navigation

For Structured Web Site Search

The Idea of Facets• Facets are a way of labeling data

A kind of Metadata (data about data) Can be thought of as properties of

items• Facets vs. Categories

Items are placed INTO a category system

Multiple facet labels are ASSIGNED TO items

The Idea of Facets• Create INDEPENDENT categories

(facets) Each facet has labels (sometimes

arranged in a hierarchy)• Assign labels from the facets to

every item Example: recipe collection

Course

Main Course

CookingMethod

Stir-fry

Cuisine

Thai

Ingredient

Bell Pepper

Curry

Chicken

The Idea of Facets• Break out all the important

concepts into their own facets• Sometimes the facets are

hierarchical Assign labels to items from any

level of the hierarchy

Preparation Method Fry Saute Boil Bake Broil Freeze

Desserts Cakes Cookies Dairy Ice Cream Sorbet Flan

Fruits Cherries Berries Blueberries Strawberries Bananas Pineapple

Using Facets

• Now there are multiple ways to get to each item

Preparation Method Fry Saute Boil Bake Broil Freeze

Desserts Cakes Cookies Dairy Ice Cream Sherbet Flan

Fruits Cherries Berries Blueberries Strawberries Bananas Pineapple

Fruit > PineappleDessert > Cake

Preparation > Bake

Dessert > Dairy > SherbetFruit > Berries > Strawberries

Preparation > Freeze

Advantages of Faceted Navigation

• Systematically integrates search results: reflect the structure of the info

architecture retain the context of previous

interactions• Gives users control and flexibility

Over order of metadata use Over when to navigate vs. when to

search

Faceted Categories vs. Hierarchies

Stickers vs. Folders

vs

Example: Medicare Prescription Drug Plan

Scam If you have folders, have to place the item into multiple folders:

Health

Elderly

Drugs

Fraud

Safety

Alternative: assign stickers to the item:

Medicare Prescription Drug Plan Scam Assign categories to the item,

rather than put the item into categories

Health

Safety

Elderly

Drugs

Scams

Physicians

Faceted Navigation

• User can start with any category, and see the results grouped by the other categories.

• Example: Start with Health

• See results grouped by subcategories of Health, such as Drugs, Nutrition

Alternatively, user can group results by other categories:

• Click on Financial, see Insurance, Payments, etc• Click on Teens, see results relevant to teens

Examples of Faceted Layouts

Examples of Faceted Layouts

Best Practices for SearchThank you!

Marti HearstWeb Manager University

November 10, 2009

Ease of Use

REDUCE STEPS

USE CLEAR LANGUAGE