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.)

 

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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	86.91	80	77.45	70	67.99	60	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.)

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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	90	93.82	80	84.12	70	74.42	60	64.72

*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.)

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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	85.2	80	76.3	70	67.4	60	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.)

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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 total	153	15	94	67.66	14.09
Weighted Total*	137	35.8	90.3	73.8	9.86	90	89	80	79	70	69	60	59

        *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.)

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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	86	78	76	68	66	58	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.)

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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 = 4.56

Exam 3:
n (number of students) = 108
range (low to high scores) = 15-33
mean = 27.3
standard deviation = 4.25

Total 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 = 10.03

sum of hand-in reports (Labs 1-12):
n (number of students) = 113
range (low to high scores) = 10-43
mean = 35.35
standard deviation = 4.66

skills 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 TWS

TWS 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	IF by normal curve (mean + or - 0.5 or 1.5 std dev)	IF by university curve (90-80-70-60 %)*	ACTUAL CUT-OFFS USED (lowest of the two scales for each grade border)
A	86.65	90	86.65
B	79.85	80	79.85
C	73.05	70	70
D	66.25	60	60

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.

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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 = 4.6

Exam 3:
n (number of students) = 169
range (low to high scores) = 8.5-34
mean = 21.9
standard deviation = 5.4

Total for exams:
n (number of students) = 174
range (low to high scores) = 21.5-99
mean = 68.9
standard deviation = 14.2

sum 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 = 5.5

skills 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 TWS

TWS 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	IF by normal curve (mean + or - 0.5 or 1.5 std dev)	IF by university curve (90-80-70-60 %)*	ACTUAL CUTOFFS USED (lowest of the two scales for each grade border)
A	90.19	90	90.0
B	81.79	80	80.0
C	73.39	70	70.0
D	64.99	60	60.0

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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 = 4.8

Exam 3::
n (number of students) = 103
range (low to high scores) = 13.5-34
mean = 24.6
standard deviation = 4.4

Total for exams:
n (number of students) = 103
range (low to high scores) = 47.5-97
mean = 71.2
standard deviation = 11.0

sum 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 = 3.6

skills 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 TWS

TWS 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	IF by normal curve (mean + or - 0.5 or 1.5 std dev)	IF by university curve (90-80-70-60 %)*	ACTUAL CUTOFFS USED (lowest of the two scales for each grade border)
A	87.3	90	87.3
B	80.0	80	80.0
C	72.6	70	70.0
D	65.3	60	60.0

 

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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	IF by normal curve (mean + or - 0.5 or 1.5 std dev)	IF by university curve (90-80-70-60 %)*	ACTUAL CUTOFFS USED (lowest of the two scales for each grade border)
A	87.6	90	87.6
B	76.2	80	76.2
C	64.8	70	64.8
D	53.4	60	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.)

 

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James W Grier
Last Updated:  (see most recent date archived)
Published by North Dakota State University