**Biology 151L -- General Biology II Laboratory: SCORE ARCHIVE**

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Most recent semester on top. (Note: scoring methods and weighting have changed from semester to semester with attempts to improve the system, based on experience and student feedback.)

Fall 2005 Score Statistics and Final Curve:

(archived 2-15-06)

The final grade for the course is based on weighted total points (not an average of component "grades")as explained in the lab manual. (Also, except for the weighted total at the bottom, the statistics for other items include missing scores which bias the calculated means and sd's downward. Only the weighted total has been corrected to exclude missing scores.)

Bold blue values are the ones actually used for determining grades (and all borderline cases are automatically reviewed by the instructor; you don't have to request a review of borderline scores).

"A" via:"B"..."C"..."D"...n min max mean=m sd 90% m+1.5sd 80% m+0.5sd 70% m-0.5sd 60% m-1.5sd Total for

Lab hand-ins

(Labs 1-12)191 22.5 92 76.9 13.4 Skills 88 7.5 20 16.15 2.8 Exam 1 185 10 33 21.85 5.1 Exam 2 177 3 31 16.70 6.3 Exam 3 168 6 32 22.92 5.5 Weighted

Total*160 42.8 93.4 72.72 9.46 90 86.9180 77.4570 67.9960 58.53

*for weighting (= % of Total): exam total x 0.5 (= 50%), lab report total x 0.3 (= 30%), skills x 1.0 (= 20%)

(Note: The weighted total score is based only on cases with complete scores, that is, excluding those with missing scores, for statistical and curve purposes.)

Spring 2005 Score Statistics and Final Curve:

(archived 8-22-05)

Bold blue values are the ones actually used for determining grades (and all borderline cases are automatically reviewed by the instructor; you don't have to request a review of borderline scores).

"A" via:"B"..."C"..."D"...n min max mean=m sd 90% m+1.5sd 80% m+0.5sd 70% m-0.5sd 60% m-1.5sd Total for

Lab hand-ins

(Labs 1 to 12)167 28.5 92 81.2 9.37 Skills 165 7 20 17.4 2.2 Exam 1 168 6 34 24.6 5.4 Exam 2 164 9 34 26.73 4.68 Exam 3 162 4 32.5 22.72 6.22 Weighted

Total*159 39 95 79.27 9.7 9093.82 8084.12 7074.42 6064.72

*for weighting (= % of Total): exam total x 0.5 (= 50%), lab report total x 0.3 (= 30%), skills x 1.0 (= 20%)

(Note: The weighted total score is based only on cases with complete scores, that is, excluding those with missing scores, for statistical and curve purposes.)

Fall 2004 Score Statistics and Final Curve:

(archived 2-15-05)

Bold blue values are the ones actually used for determining grades (and all borderline cases are automatically reviewed by the instructor; you don't have to request a review of borderline scores).

"A" via:"B"..."C"..."D"...n min max mean=m sd 90% m+1.5sd 80% m+0.5sd 70% m-0.5sd 60% m-1.5sd Total for

Lab hand-ins

(Labs 1 to 12)236 53.5 93 82.1 6.6 Skills 239 7.5 20 16.6 2.2 Exam 1 247 8 33 19.7 5.1 Exam 2 241 4 31.5 17.7 5.9 Exam 3 233 8.5 33 22.5 5.0 Weighted

Total*222 46 95.4 71.8 8.9 90 85.280 76.370 67.460 58.5

*for weighting (= % of Total): exam total x 0.5 (= 50%), lab report total x 0.3 (= 30%), skills x 1.0 (= 20%)

(Note: The weighted total score is based only on cases with complete scores, that is, excluding those with missing scores, for statistical and curve purposes.)

Spring 2004 Score Statistics and Final Curve:

(archived 10-4-04)

Bold values are the ones actually used for determining grades (and all borderline cases were automatically reviewed by the instructor; you don't have to request a review of borderline scores).

"A" via:"B"..."C"..."D"...n min max mean=m sd 90% m+1.5sd 80% m+0.5sd 70% m-0.5sd 60% m-1.5sd Total for

Lab hand-ins

(Labs 1 to 12)150 45.8 85.5 74.9 6.24 Skills 152 10.5 20 17.18 1.96 Exam 1 160 7 33 20.19 5.01 Exam 2 152 12 34 25.58 4.71 Exam 3 147 10 34 22.99 4.67 Exams

total153 15 94 67.66 14.09 Weighted

Total*137 35.8 90.3 73.8 9.86 90 8980 7970 6960 59

(Note:The weighted total score is based only on cases with complete scores, that is, excluding those with missing scores, for statistical and curve purposes.)

Fall 2003 Score Statistics and Final Curve:

(archived 1-7-04)

(The bold, red border lines are the ones that were used for determining grades. Please note: border-line cases [those just below the border] are automatically and individually considered, pending such things as progress through the semester, attendance, etc.; you don't need to ask to have them looked at -- it has already been done.)

"A" via:"B"..."C"..."D"...n min max med mean=m sd 90% m+1.5sd 80% m+0.5sd 70% m-0.5sd 60% m-1.5sd Lab 1 261 1 8 4 4.40 1.4 Lab 2 269 3 8 5 5.34 1.2 Lab 3 263 1 8 5.7 5.23 1.2 Lab 4 261 4 8 7 6.68 0.9 Lab 5 262 2 8 7 6.50 1.3 Lab 6 ... .... ..... not scored .... etc. ... (see totals next row) (Lab

total)**276 0 80 68 63.72 16.5 skills 249 5 20 16 15.49 2.8 Exam 1 254 8 33 22 21.66 5.5 Exam 2 249 6 33 23 22.69 5.2 Exam 3 246 10 34 25 24.85 4.7 (Exams

total)**276 0 96 67 62.7 23.5 Weighted

Total*234 41 90 72 71.31 9.9 88 8678 7668 6658 56

*for weighting (= % of Total): the exam total was x 0.5 (= 50%), lab report total x 0.3 (= 30%), skills x 1.0 (= 20%)**(NOT corrected for missing scores, which biases the statistics downward. Correction not worth the time and effort required for these intermediate values. However, the correction was done for determining the final weighted total as it was important and counted for determining grades.)

Spring 2003 Score Statistics and Final Curve:

(archived 8-24-03)Score statistics --

Exam 1:

n (number of students) = 112

range (low to high scores) = 13-32

mean = 25.4

standard deviation = 3.72

Exam 2:(question 19 dropped; total possible score = 33, not 34)

n (number of students) = 109

range (low to high scores) = 12-32.5

mean = 23.6

standard deviation = 4.56Exam 3:

n (number of students) = 108

range (low to high scores) = 15-33

mean = 27.3

standard deviation = 4.25Total for exams:

... for those who have taken all 3 exams (so stats aren't skewed by missing scores)

n (number of students) = 108

range (low to high scores) = 51-95.5

mean = 76.44

standard deviation = 10.03sum of hand-in reports (Labs 1-12):

n (number of students) = 113

range (low to high scores) = 10-43

mean = 35.35

standard deviation = 4.66skills demonstrations:

n (number of students) = 108

range (low to high scores) = 8.5-18

mean = 14.1

standard deviation = 1.84

TOTAL WEIGHTED SCORE (TWS):Formula for calculating weights and the final total weighted score...

TWS = (total of lab exam scores x 0.6) + ((total of hand-in reports + 42) x 0.3) + (skills demo x.0.5)*

*skills demo max score = 19, close to 20, so halved to achieve about 10 pts max, or ~ 10% of TWSTWS statistics:

n (number of students) = 107 (excluding those with missing scores, for purposes of calculating statistics)

range (low to high scores) = 58.95-89.6

mean = 76.45

standard deviation = 6.78

GRADE CURVE based on TWS

for grade IFby normal curve

(mean + or - 0.5 or 1.5 std dev)IFby university curve

(90-80-70-60 %)*ACTUAL CUT-OFFS USED(

lowestof the two scales for each grade border)A 86.6590 86.65B 79.8580 79.85C 73.05 7070D 66.25 6060

Note:Borderline cases (those falling 1 or 2 points below the grade cut-offs) will be considered on a case by case basis. They are reviewed automatically; you do not have to request it.

Fall 2002 Score Statistics and Final Curve:

(archived 1-14-03)Score statistics --

Exam 1:

n (number of students) = 173

range (low to high scores) = 12-34

mean = 25.2

standard deviation = 4.4

Exam 2:

n (number of students) = 170

range (low to high scores) = 12-34

mean = 23.8

standard deviation = 4.6Exam 3:

n (number of students) = 169

range (low to high scores) = 8.5-34

mean = 21.9

standard deviation = 5.4Total for exams:

n (number of students) = 174

range (low to high scores) = 21.5-99

mean = 68.9

standard deviation = 14.2sum of hand-in reports (Labs 1-12):

n (number of students) = 174

range (low to high scores) = 18.5-56

mean = 47.1

standard deviation = 5.5skills demonstrations:

n (number of students) = 170

range (low to high scores) = 13-19

mean = 16.5

standard deviation = 1.5

TOTAL WEIGHTED SCORE (TWS):Formula for calculating weights and the final total weighted score...

TWS = (total of lab exam scores x 0.6) + ((total of hand-in reports + 42) x 0.3) + (skills demo x.0.5)*

*skills demo max score = 19, close to 20, so halved to achieve about 10 pts max, or ~ 10% of TWSTWS statistics:

n (number of students) = 157 (excluding those with missing scores, for purposes of calculating statistics)

range (low to high scores) = 53.2-96.5

mean = 77.6

standard deviation = 8.4

GRADE CURVE based on TWS

for grade IFby normal curve

(mean + or - 0.5 or 1.5 std dev)IFby university curve

(90-80-70-60 %)*ACTUAL CUTOFFS USED(

lowestof the two scales for each grade border)A 90.19 9090.0B 81.79 8080.0C 73.39 7070.0D 64.99 6060.0

Spring 2002 Score Statistics and Final Curve:

(archived 8-21-02)

Note: Based on feedback from students in the Fall 2001 semester, the scoring and grading system was modified to better reflect weekly hand-in and skill scores, as reflected in this (and subsequent) semester's results.Score statistics --

Exam 1:

n (number of students) = 110

range (low to high scores) = 11.5-32.5

mean = 23.6

standard deviation = 4.1

Exam 2:

n (number of students) = 106

range (low to high scores) = 12.5-33

mean = 22.6

standard deviation = 4.8Exam 3::

n (number of students) = 103

range (low to high scores) = 13.5-34

mean = 24.6

standard deviation = 4.4Total for exams:

n (number of students) = 103

range (low to high scores) = 47.5-97

mean = 71.2

standard deviation = 11.0sum of hand-in reports (Labs 1-12):

n (number of students) = 105

range (low to high scores) = 31.5-51.5

mean = 42.9

standard deviation = 3.6skills demonstrations:

n (number of students) = 105

range (low to high scores) = 13.5-19

mean = 16.1

standard deviation = 1.0

TOTAL WEIGHTED SCORE (TWS):Formula for calculating weights and the final total weighted score...

TWS = (total of lab exam scores x 0.6) + ((total of hand-in reports + 42) x 0.3) + (skills demo x.0.5)*

*skills demo max score = 19, close to 20, so halved to achieve about 10 pts max, or ~ 10% of TWSTWS statistics:

n (number of students) = 103

range (low to high scores) = 60.1-94.0

mean = 76.3

standard deviation = 7.3

GRADE CURVE based on TWS

for grade IFby normal curve

(mean + or - 0.5 or 1.5 std dev)IFby university curve

(90-80-70-60 %)*ACTUAL CUTOFFS USED(

lowestof the two scales for each grade border)A 87.390 87.3B 80.08080.0C 72.6 7070.0D 65.3 6060.0

## Scores and final grade borderlines from Fall Semester 2001:

(archived 1-15-02)## Score statistics --

Exam 1:n (number of students) = 154

range (low to high scores) = 13-32

mean = 24.7

standard deviation = 3.6

Exam 2:n (number of students) = 152

range (low to high scores) = 11-34

mean = 23.6

standard deviation = 5.2

Exam 3:n (number of students) = 149

range (low to high scores) = 11-31

mean = 21.8

standard deviation = 5.2

TOTAL FOR ALL 3 EXAMS:n (number of students) = 148

range (low to high scores) = 44-94

mean = 70.5

standard deviation = 11.4

for grade IFby normal curve

(mean + or - 0.5 or 1.5 std dev)IFby university curve

(90-80-70-60 %)*ACTUAL CUTOFFS USED(

lowestof the two scales for each grade border)A 87.690 87.6B 76.280 76.2C 64.870 64.8D 53.460 53.4(Note: Grades for borderline cases as well as incomplete scores, including missing or low hand-in and skills scores, are determined by considering weekly reports and skill demonstration scores. See original syllabus and the lab manual for that semester for further explanations.)

James W Grier

Last Updated: (see most recent date archived)

Published by North Dakota State University