38.2.1.2 Repeated Measures. A variation of the above experimental
design is the situation where all treatments (X1, X2,
etc.) are administered to all subjects. Thus, each individual (S1,
S2, etc.), in essence, serves as his or her own control and is
tested or “observed” (O), as diagrammed below for an experiment
using n subjects and k treatments. Note that the diagram
shows each subject receiving the same sequence of treatments;
a stronger design, where feasible, would involve randomly ordering
the treatments to eliminate a sequence effect.
S1: X10−X20 ... XkO.
S2: X10−X20 ... XkO.
Sn: X10−X20 ... XkO.
Suppose that an experimenter is interested in whether learners
are more likely to remember words that are italicized or
words that are underlined in a computer text presentation.
Twenty subjects read a paragraph containing five words in each
form. They are then asked to list as many italicized words and as
many underlined words as they can remember. (To reduce bias,
the forms in which the 10 words are represented are randomly
varied for different subjects.) Note that this design has the advantage
of using only one group, thereby effectively doubling the
number of subjects per treatment relative to a two-group (italics
P1: MRM/FYX P2: MRM/UKS QC: MRM/UKS T1: MRM
PB378-38 PB378-Jonassen-v3.cls August 30, 2003 14:50 Char Count= 0
only vs. underline only) design. It also ensures that the ability
level of subjects receiving the two treatments will be the same.
But there is a possible disadvantage that may distort results. The
observations are not independent. Recalling an italicized word
may help or hinder the recall of an underlined word, or vice
versa.
38.2.1.2 Repeated Measures. A variation of the above experimentaldesign is the situation where all treatments (X1, X2,etc.) are administered to all subjects. Thus, each individual (S1,S2, etc.), in essence, serves as his or her own control and istested or “observed” (O), as diagrammed below for an experimentusing n subjects and k treatments. Note that the diagramshows each subject receiving the same sequence of treatments;a stronger design, where feasible, would involve randomly orderingthe treatments to eliminate a sequence effect.S1: X10−X20 ... XkO.S2: X10−X20 ... XkO.Sn: X10−X20 ... XkO.Suppose that an experimenter is interested in whether learnersare more likely to remember words that are italicized orwords that are underlined in a computer text presentation.Twenty subjects read a paragraph containing five words in eachform. They are then asked to list as many italicized words and asmany underlined words as they can remember. (To reduce bias,the forms in which the 10 words are represented are randomlyvaried for different subjects.) Note that this design has the advantageof using only one group, thereby effectively doubling thenumber of subjects per treatment relative to a two-group (italicsP1: MRM/FYX P2: MRM/UKS QC: MRM/UKS T1: MRMPB378-38 PB378-Jonassen-v3.cls August 30, 2003 14:50 Char Count= 0only vs. underline only) design. It also ensures that the abilitylevel of subjects receiving the two treatments will be the same.แต่มีข้อเสียก็เป็นไปได้ที่อาจบิดเบือนผล การสังเกตจะไม่เป็นอิสระ นึกถึงคำเป็นตัวเอียงอาจช่วย หรือขัดขวางการเรียกคืนของคำที่ขีดเส้นใต้ หรือรองในทางกลับกัน
การแปล กรุณารอสักครู่..
