How to analyse text and websites for reading age

I have been looking for a method to analyse digital text for reading age, this could be online stories, news sites, topic reference websites, or you could just type in a piece of text from a paper based story.

What I found was Lexile Analyzer from

A Lexile Text Measure is based on the two predictors (word frequency and sentence length) of how difficult a text is to comprehend. 

To prepare your text for measurement you need to follow the instruction here. Basically for a website you need to strip out the text from banners, headers and other unrelated text that could alter the results. For paper text you can just type in the story or just cut and paste for digital stories or text.  If a text is too long, you can also just type in a portion of the story. This does change results as you will see below, in this case making it less accurate. I am looking at this from a guided reading perspective, so possibly if the Lexile measure is viewed as an independent reading level, you may get different result. As usual teacher judgment is called for.

In order to test this, I chose a New Zealand Journal Surf article, "Worms for Dinner?" (Part 01, Number 5, 2008, pages 7-10) with a Guided Reading Level of 9.5-10.5 years. The New Zealand Primary Schools Reading Age Guide shows this age as a Level 28. In Year 5 (New Zealand) students are around 9 years of age.

For the first test I typed in the whole story of 246 words, then I tested a smaller portion of 141 words.

Test Results 1

Word Count 246

Lexile measure 760L (Grade 5; age 9 - Lexile Text Measures by Grade)

Mean Sentence Length 11.18

Mean Log Word Frequency 3.52

Test Results 2

Word Count 141

Lexile measure 680L (Grade 4; age 8 - Lexile Text Measures by Grade)

Mean Sentence Length 10.07

Mean Log Word Frequency 3.53

This convinced me that it is an accurate enough tool for me to use to gauge texts when I have no idea of the reading level. Below are the Lexile Measures as well as the NZ Reading Age Guide to compare.

Lexile Text Measures by Grade

Grade	Approx Age	Text Measures (from the Lexile Map) 25th - 75th percentile
1	5	200L to 400L
2	6	300L to 500L
3	7	500L to 700L
4	8	650L to 850L
5	9	750L to 950L
6	10	850L to 1050L
7	11	950L to 1075L
8	12	1000L to 1100L
9		1050L to 1150L
10		1100L to 1200L
11 and 12		1100L to 1300L

New Zealand Primary Schools Reading Age Guide

Reading  age	Level	Colour
12 - 14 years	31
11 - 12 years	30
10 - 11 years	29
9.6  - 10 years	28
9.0  - 9.6  years	27
8.6  - 9.0  years	26
	25
8.0  - 8.6  years	24
	23
7.6  – 8.0  years	22	Gold
	21	Gold
7.0  – 7.6  years	20	Purple
	19	Purple
6.6  – 7.0  years	18	Turquoise
	17	Turquoise
6.0  – 6.6  years	16	Orange
	15	Orange
5.6  – 6.0  years	14	Green 3
	13	Green 2
	12	Green 1
	11	Blue 3
	10	Blue 2
	9	Blue 1
5.0  – 5.6  years	8	Yellow 3
	7	Yellow 2
	6	Yellow 1
	5	Red 3
	4	Red 2
	3	Red 1
Pre reading	2	Magenta
	1	Magenta

Lixile also lets you search for books by Lexile measure, age range or by difficulty. You can also look up specific books for example "Harry Potter and the Order of the Phoenix" by J.K. Rowling, has a Lexile of 950L, and a reading age of 9 - 12.

Can you see a use for this in your literacy teaching this year?