Readability analysis
The readability analysis in TextQuest is based on formulas. These are most based on the two variables that explain the most variance of reading behaviour (comprehension or speed): the sentence length and the word length.
Currently 68 formulas for 7 languages are implemented. The results of the formulas are:
- index value: 0 (difficult) up to 100 (very easy)
- reading grade: school class
- reading age: in years
The following formulas are currently implemented:
- Englisch: 31 formulas
- ARI: Smith/Kincaid 1970 reading grade and reading age
- CM1, CM2: Coleman 1965
- CLF: Coleman-Liau 1975
- DC: Dale-Chall 1948
- NDC: New Dale-Chall: Powers u.a. 1958
- DB1: Danielson/Bryan 1963
- DB2: Danielson/Bryan 1963
- EFLAW: McAlpine 1997
- FK: Flesch-Kincaid 1953 reading grade and reading age
- FOG: Gunning 1952
- FC: Forcast 1973 reading grade and reading age
- Fry 1968
- LIX: Björnsson 1968
- LW: Linsear Write
- Reading Ease Index (REI): Flesch 1948
- Modified Reading Ease Index (MREI): Powers 1958
- New Reading Ease Index (NREI): Farr, Jenkins, Paterson 1951
- Modified new reading ease index (MNREI): Powers 1958
- PSK: Powers, Sumner, Kearl 1958 reading grade and reading age
- RIX: Andersson 1983
- SMOG: McLaughlin 1969 reading grade and reading age
- SMOG2-G: McLaughlin 1969
- Spache 1953 and 1978
- WSI: Wheeler-Smith 1954
- German: 21 formulas
- AVI: Amstad 1978
- DS: Dickes-Steiwer 1977
- Fucks 1955
- FDK: Fasse dich kurz (Schirm 1972)
- G-LIX: LIX for German prose- and non-fictinoal text
- G-RIX: RIX for German prose- and non-fictinoal text
- G-SMOG: SMOG for German
- G-WSI: WSI for German
- QU: Bamberger, Vanecek 1984
- TB1: Tränkle, Bailer 1984
- TB2: Tränkle, Bailer 1984
- TRI: Text-Redundanz-Index Kuntzsch 1981
- 4 Vienna non-fiction formulas (Sachtextformeln) Bamberger, Vanecek 1984
- 3 Vienna fiction formulas (Literaturtextformeln) Bamberger, Vanecek 1984
- Spanish
- CSRI: Childrens Spanish Reading Index Crawford 1984
- Huerta: Huerta 1959
- Gutierrez: Gutierrez 1972
- Dutch
- Brouwer: Brouwer 1963
- Dourma: Dourma 1960
- Staphorsius: Staphorsius and Krom 1985
- Danish: DK-LIX: Jakobsen 1971
- French: KM: Kandel and Moles 1958
- Swedish: S-LIX: Lix for Swedish, Björnsson 1968, 1983

All formulas are computed as raw and as standardised values. Some formulas require tables, also these values are computed. Additionally all variables used for the computation are computed, therefore it is possible to compute own formulas by just inserting the computed values.
The results look like this:
raw value standard formula
- R 01: 299.530 29.967 Coleman 1
- R 02: 302.970 31.062 Coleman 2
- R 03: 4.659 4.659 Danielson-Bryan 1
- R 04: 367.365 33.232 Farr-Jenkins-Paterson: New Reading Ease Index: 11
- R 05: -480.715 51.658 Flesch's Reading Ease Index: 10
- R 06: 19.904 19.904 LIX: 4. class
- R 07: 49.070 20.437 Power's Modified Reading Ease Index: 12
- R 08: 196.448 61.040 Power's Modified New Reading Ease Index: 8
- R 09: 2.840 2.840 RIX: 7. class
- R 10: 24.400 24.400 Wheeler-Smith-Index: 4