検索エンジン最適化 (SEO)

トピック

Google 検索にブログをインデックスさせる
検索エンジンへのサイト登録
検索エンジン最適化リソース
その他のリソースとチュートリアル

WordPress はインストールするだけでも検索エンジンと相性が良い状態になっています。デフォルト機能により、検索エンジンが個別投稿・固定ページ・カテゴリーなどをクロールして情報を検索データベースに含めやすいようになっています。

WordPress にはビルトインで検索エンジン最適化 (SEO) ツールが含まれています。.htaccess を使った「パーマリンク」と呼ばれるきれいな URL の生成、Ping (ピンバック) の送信などです。他にも SEO に使える多数のサードパーティプラグインがあります。

しかし、さまざまな WordPress テーマを使ったり、自身の目的に合わせて WordPress をカスタマイズし始めると、検索エンジンにフレンドリーなデフォルト機能が動作しなくなってしまう恐れがあります。WordPress サイトが検索エンジンのスパイダーやクローラーに対して最もフレンドリーな状態を保つためには、以下のようなことに気をつけてください。

正しくクリーンなコード

サイトのコードが検証にパスしているよう確認してください。コードにエラーがあると、検索エンジンがサイト内を正常に移動できない可能性があります。

コンテンツに「語りかける」

検索エンジンは、サイトを「見る」ことはできず、「読む」ことしかできません。ビジュアル的な見た目では検索エンジンと対話することはできません。検索エンジンに「語りかける」のは、言葉であり、コンテンツであり、サイト内の説明、共有、情報提供、教育、会話などの素材です。検索エンジンが良いスコアをつけるためには、すべてのパーツを確認・比較して、必ず質の高い言語コンテンツがあるようにしてください。

検索者を意識してコンテンツを書く

インターネットで情報を見つけるにはどうすればよいか、考えてみましょう。もしインターネット上で「見つけてもらいたい」と思って何かを書いているのであれば、誰かがその情報を見つけるために使うであろう言葉やフレーズについて考えてみてください。そのフレーズを書くときには、すべての文章内に含める必要はありませんが、1回だけではなく複数回使うようにしましょう。検索エンジンがあなたのコンテンツをどのようにスキャンし、評価し、分類しているかを学ぶことで、検索エンジンに好意的に受け入れられるようになります。

コンテンツファースト

検索エンジンがサイトでスキャンを開始すると、ほとんどの場合、スタイルや CSS を無視します。検索エンジンは、コンテンツや情報を収集するために、サイト内を走り回ります。ほとんどの WordPress テーマは、スタイルのないページの上部にコンテンツを配置し、サイドバーやフッターは下部に配置するように設計されています。ほとんどの検索エンジンは、ページの最初の3分の1以上をスキャンしてから次に進みます。テーマ内では、コンテンツが一番上に来るようにしましょう。

キーワード、リンク、タイトルとコンテンツを一致させる

検索エンジンは、サイトの美しさを評価するのではなく、単語を評価し、ふるいにかけ、特定の単語や単語の組み合わせに評価を与えます。文書の中にある単語と、リンクやタイトルの中にある単語が比較されます。一致するものが多ければ多いほど、その「スコア」は高くなります。

リンクと画像内のコンテンツ

Your site may not have much text, mostly photographs and links, but you have places in which to add textual content. Search engines look for alt and title in link and image tags. While these have a bigger purpose of making your site more accessible, having good descriptions and words in these attributes helps provide more content for search engines to digest.

リンクポピュラリティ (人気度)

It is not how good your site is, it is how good the sites are that link to you. This still holds weight with search engine favoritism. It’s about who links to you. Blogrolls, pingbacks, and trackbacks are all built into WordPress. These help you link to other people, which gives them credit, but it also helps them link to you, connecting the “links.” The number of incoming links your site has that have been recognized by Google can be checked by typing link:www.yoursite.com into Google (other search engines have similar functions). Other ways to generate incoming links to your site include:

Add your site’s url to your signature on forum posts on other sites.
Submit your site to directories (see below).
Note: Leaving comments on blogs will not help with this, since all modern blogging tools use the rel=”nofollow” attribute. Don’t be a comment spammer.

良質なナビゲーションリンク

A search engine crawls through your site, moving from page to page. Good navigational links to the categories, archives, and various pages on your site will invite a search engine to move gracefully from one page to another, following the connecting links and visiting most of your site.

Google 検索にブログをインデックスさせる

Before getting to the details on how you can get Google to recognize you, we need to first understand these three terms:

The Googlebot: This is the software used to search that is used by Google to gather new information that has been uploaded online so that it can be fed on Google pages. Once information that you had uploaded is picked up by this software, then it can be found on Google pages.
Crawling: This is the process where the above named software, Googlebot, roams from site to site detecting any new information to be uploaded on Google. This software works by going through new links that have been uploaded recently and which are generating a lot of traffic.
Indexing: Once the information has been gathered by the Googlebot through the process called crawling, it is processed through another process called indexing. It is through this process that the quality of content is determined so that they can be placed appropriately on Google pages. The question now is, how exactly does Googlebot find this information? Firstly, it starts by siting the web pages that it had cited in the previous search. It then detects new pages associated with those old ones or just new ones all together. More details on the same would be found on Search Console help for those who are interested in the same. Any new information is cited with the help of sitemaps and links that lead to those articles.

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検索エンジンへのサイト登録

There are many resources that will “help” you submit your site to search engines. Some are free, some for a fee. Or you can manually submit your site to search engines yourself. Whatever method you choose to use, once your site has been checked for errors and is ready to go, search engines will welcome your WordPress site.

Here are some tips for successful site submissions:

Make sure you have content for search engines to scan. In general, have more than 10 posts on your site to give the search engines something to examine and evaluate.
Do not submit your site to the same search engine more than once a month or longer, depending upon their criteria, not your anxiousness to be listed.
Have ready to type, or copy and paste, the title of the site, and the categories your site may belong to in a search engine directory.
Have a list of your website’s various “addresses/URLs” ready. You can submit your root directory as well as specific categories and feeds to search engines, expanding your search engine coverage.
Keep a list of the various search engines and directories you submit to so you do not accidentally resubmit too soon, and you can keep track of how they include you among their pages and results.

Directory Sites

It is also useful for traffic generation and search optimization purposes to submit your site to directories. Both comprehensive directory sites and those specific to the subject or localisation of your site can be used.

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検索エンジン最適化リソース

While WordPress comes ready for search engines, the following are more resources and information you may want to know about preparing and maintaining your site for search engines’ robots and crawlers.

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メタタグ

Meta Tags contain information that describes your site’s purpose, description, and keywords used within your site. The meta tags are stored within the head of your header.php template file. By default, they are not included in WordPress, but you can manually include them and the article on Meta Tags in WordPress takes you through the process of adding meta tags to your WordPress site.

The WordPress Custom Fields option can also be used to include keywords and descriptions for posts and Pages. There are also several WordPress Plugins that can also help you to add meta tags and keyword descriptions to your site found within the Official WordPress Plugin Directory.

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robots.txt 最適化

Search Engines read a file at yourdomain.com/robots.txt to get information on what they should and shouldn’t check.

Adding entries to robots.txt to help SEO is popular misconception. Google says you are welcome to use robots.txt to block parts of your site but these days prefers you don’t. Use page-level noindex tags instead, to tackle low-quality parts of your site. Since 2009, Google has been evermore vocal in its advice to avoid blocking JS & CSS files, and Google’s Search Quality Team has been evermore active in promoting a policy of transparency by webmasters, to help Google verify we’re not “cloaking” or linking to unsightly spam on blocked pages. Therefore the ideal robots file disallows nothing whatsoever, and may link to an XML Sitemap if an accurate one has been constructed (which itself is rare though!).

WordPress by default only blocks a couple of JS files but is nearly compliant with Google’s guidance here.

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追加リソース

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フィードの登録

WordPress comes built-in with various feeds, allowing your site to be viewed by various feed readers. Many search engines are now accepting feed submissions, and there are many site which specialize in directories of feeds and feed services.

To submit your site’s feeds, you need to know the link to the various feeds your site provides. The article WordPress Feeds lists the various links of the feeds that come built into WordPress.

For information on customizing these links, see the article on Customizing Feeds.

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パーマリンク

Permalinks are enhancements to your existing URLs which can improve search engine optimization by presenting your post, page, and archive URLs as something like <nowiki>http://example.com/2003/05/23/my-cheese-sandwich/</nowiki> rather than <nowiki>http://example.com/index.php?p=423</nowiki>. See Using Permalinks for more information.

As search engines use links and the title as part of their information gathering, links to posts and articles within your site gain importance with Permalinks.

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サイトマップ

A sitemap or “site map” is a single page listing of all the posts on your website. It is intended for your visitors to get a good overview on what your site is about and to find a blog post quickly but it also has great benefits in the search engines as a good link is always pointing to all your blog posts. By having a link to your sitemap on all your sites pages both visitors and search engines will easily get to it and find all your posts.

Here is a tutorial with three different examples of sitemaps with demos and how to set them up:

Tutorial: Automatic Sitemap for WordPress

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Google サイトマップ

As of June 2005, Google is now accepting sitemaps of your site as part of their website submissions. Google needs to have this sitemap formatted in a special way using XML. You can find more information about Google’s Sitemap Submissions from Google, and the discussion on the WordPress Forum about WordPress and Google Site maps.

Some utilities have been created to help the WordPress user to create a Google site map of their site for submission to Google. For more information on these and Google sitemaps:

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