TEDS Data Dictionary

The 10 Year General Knowledge Web Test

Contents of this page:

Introduction

This page describes the General Knowledge test that was used in the 10 Year twin web study.

Description of Test

The test consists of a series of general knowledge questions. For each question, there are four possible responses; the twin selects a response by clicking on it on the screen. There are 30 items: the questions and responses are tabulated below. A twin taking the test may be presented with fewer than 30 items, because of the branching and discontinue rules, which are described below.

Each item is presented in two ways: as text on the screen, and as an audio recording. The text and audio file for each item are downloaded immediately before the item is presented. The audio recording was included as an aid to any twins with reading difficulties; this test was not intended to assess reading ability in addition to general knowledge.

Test Rules

Note that this test did not have an item timeout rule.

  • Scoring
    For each question, the correct response is given a score of 1, and any of the three incorrect responses is given a score of 0. The maximum total score for the test is 30.
  • Branching rules
    • Start at item 5, and proceed to item 6.
    • If both items 5 and 6 are correct (scoring 1 each), give credit for items 1-4 (as though they had been answered correctly, gaining a score of 1 for each item), then proceed upwards from item 7.
    • If either item 5 or item 6 is incorrect (scoring 0), attempt the lower items (1-4) in reverse order. Then:
      • If any two successive items are correct (e.g. 4 and 3), then give credit for any of items 1-4 not yet attempted; then proceed upwards from item 7. Note that if either item 5 or item 6 is correct, and this is followed by a correct answer for item 4, then this results in an upward branch to item 7 (items 5 and 4 are treated as successive items, as are items 6 and 4, for this rule).
      • If no two successive items are correct, the test ends after item 1 has been attempted.
  • Discontinue rules
    Discontinue the test after five scores of zero in any six consecutive items. This rule applied throughout the test after five or more items had been attempted.

Item Variables

The item variables relating to the General Knowledge test, as listed in the table below, were generated automatically by programs on the web server during the course of the test. Note that the dataset only includes data for completed tests. If a twin started the test but left it unfinished, then the data for the test were not used.

In most cases the values of these variables have been left unaltered, although some have been recoded during data cleaning. See the web data cleaning page for further details.

  • For items skipped due to the discontinue rule, the item response variable is recoded from missing to -2, and the item score is recoded from missing to 0.
  • For items skipped and credited due to upward branching, the item response variable is recoded from missing to -3 (the item score is already recorded as 1 on the web server).
  • For items that crashed or malfunctioned in any way, the item response variable is recoded from missing to -4, and the item score is recoded from missing to 0.
  • For twins identified as random responders in this test, the status flag is recoded from 2 to 4, the data flag is recoded from 1 to 0, and all item variables are recoded to missing (test data deleted)

The start and end dates and times have not been retained in the dataset.

VariablesExplanationValues
jgstat1/2 Test status: outcome of test 0=not started, 1=started but not finished, 2=successfully completed, 4=random responses
jgdata1/2 Data flag: is test data present in the dataset? 0=no, 1=yes
jgstdt1/2 Start date of the test [not in dataset] Date values
jgsttm1/2 Start time of the test [not in dataset] Time values
jgendd1/2 End date of the test [not in dataset] Date values
jgendt1/2 End time of the test [not in dataset] Time values
jgsess1/2 Number of sessions (at the computer) used by the twin to complete the test. Integer values of 1 or above
jgtime1/2 Time taken to complete the test, in seconds Integer values (number of seconds)
jg01a1/2 through to jg30a1/2 Item response (see table of items below for details) 1=A, 2=B, 3=C, 4=D.
Also -2=discontinued, -3=credited due to upward branching, -4=item crashed.
jg01s1/2 through to jg30s1/2 Item score (see table of items below for details) 0=incorrect, 1=correct
jg01at1/2 through to jg30at1/2 Answer time: length of time (in seconds) taken by the twin to respond to this item Integer values (number of seconds)
jg01dt1/2 through to jg30dt1/2 Download time: length of time (in seconds) between the end of the previous item and the start of this item; time needed to download files for this item Integer values (number of seconds)
jg01o1/2 through to jg30o1/2 Order or sequence of this item in the test; dependent on the branching path taken by the twin through this test Integer values of 1 or above

Test Items

The numbering of the items, shown in the table below, equates to the numbering used in the item variables. Note that this is not the same as the order in which items were presented to twins in the test (see branching rules above).

itemquestionresponse Aresponse B response Cresponse Dcorrect response
1What do you call this?General Knowledge test item 1 image of a nose Neck Toes EyesNoseD
2How many ears do you have?12 3 4B
3How many legs does a dog have?2 3 4 5C
4What is the day that comes after Thursday?Monday Tuesday WednesdayFridayD
5What must you do to make water boil?Heat it Put water in it Put eggs in Stir itA
6Name two kinds of coinsFrench and German Pound and PennyQueen and FlowerMoney and Five Pound Note B
7What month comes right after March?April May June FebruaryA
8How many days are there in a week?2 5 7 10C
9What are the four seasons of the year?Summer, Autumn, Winter, Spring Halloween, Mother’s Day, Christmas, Easter Sunny, Rainy, Windy, SnowyHot, Warm, Cool, ColdA
10How many things make a dozen?SixTwelve EggsTenB
11How many hours are there in a day?8 12 24 60C
12What does the stomach do?Digests foodGrowls BreathesSwallowsA
13Who was Christopher Columbus?He was president He was a pilgrimHe discovered AmericaHe was an inventor C
14Name three oceansSalt Lake, Nile, Gulf of Mexico River, Lake, SeaIndian, Pacific, AtlanticStream, Pond, CreekC
15Which month has one extra day every four years? JanuaryFebruaryMayDecemberB
16In what direction does the sun set?North EastSouthWestD
17How is oxygen returned to the air?By breathing By plantsBy the windBy cloudsB
18On what continent is Brazil?South Africa AsiaSouth AmericaEuropeC
19What is water made of?Hydrogen and oxygen RainHelium and oxygenMinerals and chemicalsA
20Who invented the electric light bulb?Albert Einstein Thomas EdisonBenjamin FranklinThomas JeffersonB
21What country in the world has the largest population? AfricaRussiaNew YorkChinaD
22Who was Anne Frank?A singerA pilot A girl who wrote a diaryA teacher of deaf and blindC
23What are hieroglyphics?Ancient Greek letters Roman numeralsEgyptian picture writingCave paintings C
24What is the main material used to make glass?Plastic SandHydrogenFibreglassB
25What is the capital of Greece?RomeCairo CreteAthensD
26What causes iron to rust?AcidOxygen SaltMineralsB
27What is a barometer?It measures rainfallIt measures wind speedIt measures air pressureIt measures earthquakesC
28Who was Charles Darwin?He was a poetHe discovered the structure of DNAHe was a character in a Dickens novelHe developed the theory of evolutionD
29How far is it from London to New York?200 miles 3,000 miles9,000 miles40,000 milesB
30What does turpentine come from?Conifer trees VarnishAcidEthyl AlcoholA