**SHRDLU**是由特里·威诺格拉德于1968年至1970年在麻省理工学院开发的一种早期的自然语言理解電腦程式 。在該程式中，用户可以與電腦对话，對這種精簡的" 积木世界"的內部状态進行移动物體、命名集合、查询等操作（积木世界本质上是一个虛擬盒子，內部充满了不同积木）。

SHRDLU是以Micro Planner和Lisp编程语言在DEC PDP-6電腦和DEC图形终端上编写而成 。 后来在犹他大学的计算机图形实验室进行了補充，加入了對SHRDLU"世界"的完整3D渲染。 

名称「SHRDLU」衍生自ETAOIN SHRDLU， ETAOIN SHRDLU是Linotype排字机上字母键配置，也就是照字母使用频率，以降序方式排列的12個字母序列。

功能
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SHRDLU主要是一种语言解析器，它允许用户使用英语术语进行互動 。 用户指示SHRDLU在"積木世界"中移动各种物體，包含各种基本物體：積木（塊體）、錐體、球體等。 SHRDLU的独特之处在於將四个简单想法的组合起來，這些想法加總在一起，使得在對"理解力"的模拟上，更具说服力。 

其中一個原因是，SHRDLU的世界非常簡單，以致於整個物體和位置的集合可以透過大約50個單詞來描述：名詞如"積木"（block）和"錐體"（cone），動詞如"放置在"（place on）和"移動到"（move to），以及形容詞如"巨大的"（big）和"藍色的"（blue）。這些基本的語言建築模塊的可能組合相當簡單，程式完全有辦法弄懂用戶的意思。 

SHRDLU還包括一個基本記憶體來提供語境。人們可以要求SHRDLU「把綠錐放在紅塊上」，然後「把錐子拿下來」；「錐體」會被認為是指剛才說的綠錐。在大多數情況下，當提供了額外的形容詞時，SHRDLU可以透過互動進一步回溯尋找合適的語境。用戶也可以問一些歷史問題，比如「在撿到錐體之前，你有沒有撿過任何東西？」 

這種記憶體的附帶效果，也是SHRDLU標准配置的基本規則，即该程式可以回答關於世界上什麼問題是可能的，什麼問題是不可能的。SHRDLU會透過尋找例子推斷出積木可以堆疊，但在嘗試過三角形後，會了解到三角形不能堆疊。"世界"包含了使積木掉落的基本物理機制 ，而這与语言解析器无关。 

最後，SHRDLU還可以記住物體的名稱或它們的排列方式。例如，人們可以說 "尖塔是一個高大的長方形上面的小三角形"；SHRDLU就可以回答積木世界中關於尖塔的問題，並建造新的尖塔。

選錄
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这是SHRDLU的著名演示：  

> 
> 人：Pick up a big red block.
> 電腦： OK.
> 人：Grasp the pyramid.
> 電腦：I DON'T UNDERSTAND WHICH PYRAMID YOU MEAN.
> 人：(changing their mind): Find a block which is taller than the one you are holding and put it into the box.
> 電腦：BY "IT", I ASSUME YOU MEAN THE BLOCK WHICH IS TALLER THAN THE ONE I AM HOLDING.
> 電腦：OK.
> 人：What does the box contain?
> 電腦：THE BLUE PYRAMID AND THE BLUE BLOCK.
> 人: What is the pyramid supported by?
> 電腦：THE BOX.
> 人：How many blocks are not in the box?
> 電腦：FOUR OF THEM.
> 人：Is at least one of them narrower than the one which i told you to pick up?
> 電腦：YES, THE RED CUBE.
> 人：Is it supported?
> 電腦：YES, BY THE TABLE.
> 人：Can the table pick up blocks?
> 電腦：NO.
> 人：Can a pyramid be supported by a block?
> 電腦：YES.
> 人：Can a pyramid support a pyramid?
> 電腦：I DON'T KNOW.
> 人：Stack up two pyramids.
> 電腦：I CAN'T.
> 人：Will you please stack up both of the red blocks and either a green cube or a pyramid?
> 電腦：OK.
> 人：Which cube is sitting on the table?
> 電腦：THE LARGE GREEN ONE WHICH SUPPORTS THE RED PYRAMID.
> 人：Is there a large block behind a pyramid?
> 電腦：YES, THREE OF THEM: A LARGE RED ONE, A LARGE GREEN CUBE, AND THE BLUE ONE.
> 人：Put a small one onto the green cube which supports a pyramid.
> 電腦：OK.
> 人：Put the littlest pyramid on top of it.
> 電腦：OK.
> 人：Does the shortest thing the tallest pyramid's support supports support anything green?
> 電腦：YES, THE GREEN PYRAMID.
> 人：What color is it?
> 電腦：BY "IT", I ASSUME YOU MEAN THE SHORTEST THING THE TALLEST PYRAMID'S SUPPORT SUPPORTS.
> 電腦：RED
> 人：How many things are on top of green cubes?
> 電腦：I'M NOT SURE WHAT YOU MEAN BY "ON TOP OF "IN THE PHRASE "ON TOP OF GREEN CUBES ".
> DO YOU MEAN:
> 
> 1 - DIRECTLY ON THE SURFACE
> 2 - ANWHERE ON TOP OF ?
> 
> 人：2
> 電腦：THREE OF THEM.
> 人：Had you touched any pyramid before you put the green one on the little cube?
> 電腦：YES, THE GREEN ONE.
> 人：When did you pick it up?
> 電腦：WHILE I WAS STACKING UP THE RED CUBE, A LARGE RED BLOCK AND A LARGE GREEN CUBE.
> 人：Why?
> 電腦：TO GET RID OF IT.
> 人：Why did you do that?
> 電腦：TO CLEAN OFF THE RED CUBE.
> 人：Why did you clear off that cube?
> 電腦：TO PUT IT ON A LARGE GREEN CUBE.
> 人：Why did you do that?
> 電腦: TO STACK UP THE RED CUBE , A LARGE RED BLOCK AND A LARGE GREEN CUBE.
> 人：Why did you do that?
> 電腦：BECAUSE YOU ASKED ME TO.
> 人：How did you do it?
> 電腦：BY PUTTING A LARGE RED BLOCK ON THE TABLE ; THEN LETTING GO OF IT ; THEN PUTTING A LARGE GREEN CUBE ON IT ; THEN LETTING GO OF THAT CUBE ; THEN PUTTING THE RED CUBE ON THAT CUBE; THEN LETTING GO OF THAT CUBE.
> 人：How many objects did you touch while you were doing it?
> 電腦：FOUR OF THEM.
> 人：What did the red cube support before you started to clean it off?
> 電腦：THE GREEN PYRAMID.
> 人：There were five blocks to the left of the box then.
> 電腦：NO, ONLY FOUR OF THEM: THE RED CUBE, TWO LARGE GREEN CUBES AND A LARGE RED BLOCK.
> 人：Put the blue pyramid on the block in the box.
> 電腦：OK.
> 人：Is there anything which is bigger than every pyramid but is not as wide as the thing that supports it?
> 電腦：YES, THE BLUE BLOCK.
> 人：Does a steeple
> 電腦 (interrupting)：SORRY, I DON'T KNOW THE WORD "STEEPLE".
> 人：A "steeple" is a stack which contains two green cubes and a pyramid.
> 電腦：I UNDERSTAND.
> 人：Are there any steeples now?
> 電腦：NO.
> 人：Build one.
> 電腦：OK.
> 人：Call the biggest block "superblock".
> 電腦：OK.
> 人：Have you picked superblock up since we began?
> 電腦：YES.
> 人：Why did you drop it?
> 電腦：BY "IT", I ASSUME YOU MEAN THE SUPERBLOCK.
> I CAN'T EXPLAIN A NON-EXISTENT EVENT.
> 人：Is there anything to the right of the red pyramid?
> 電腦：YES, FOUR THINGS: THE BOX , THE RED CUBE, THE BLUE PYRAMID AND THE BLOCK NAMED SUPERBLOCK
> 人：Thank you.
> 電腦：YOU'RE WELCOME!
>

影響
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SHRDLU被认为是人工智能一次極其成功的演示。这导致其他AI研究人员过分乐观，但后来的系统試圖處理現實中的更具模糊性和複雜性的情況時[來源請求]，这种乐观情绪很快就消失了。后续與SHRDLU同型的工作（例如Cyc ）則傾向於專注為程式提供更加豐富的資訊，藉此從中獲得結論。 

尽管不是有意為之，但是SHRDLU被认为是文字冒险游戏第一个已知的正式實例，這是因为用户能夠以简单的指令在虚拟环境中移动物體來进行互動，尽管缺乏了常見於文字冒险游戏中特有的故事敘述。 1976-1977年的游戏《巨洞冒險》被广泛认为是文字冒险游戏的第一個真正作品。

參見
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* 规划器编程语言

参考文献
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1. ↑  Winograd, Terry.. 1971-01-01 （美国英语）.
2. ↑ . Stanford Human-Computer Interaction (HCI) Group. （原始内容存档于2020-08-16）.
3. ↑  Montfort, Nick.. Cambridge: The MIT Press. 2003: 84–85. ISBN 0-262-13436-5.

* Terry Winograd, "Procedures as a Representation for Data in a Computer Program for Understanding Natural Language"（页面存档备份，存于）, MIT AI Technical Report 235, February 1971
* *Understanding Natural Language* by T. Winograd, Academic Press, 1972

外部链接
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* SHRDLU（页面存档备份，存于） – Terry Winograd's SHRDLU page, includes source code
* SHRDLU resurrection（页面存档备份，存于） – re-written versions of SHRDLU, including a Java3D version