NAME: AmesHousing.txt
TYPE: Population
SIZE: 2930 observations, 82 variables
ARTICLE TITLE: Ames Iowa: Alternative to the Boston Housing Data Set
DESCRIPTIVE ABSTRACT: Data set contains information from the Ames Assessor�s Office used in computing assessed values for individual residential properties sold in Ames, IA from 2006 to 2010.
SOURCES:
Ames, Iowa Assessor�s Office
VARIABLE DESCRIPTIONS:
Tab characters are used to separate variables in the data file. The data has 82 columns which include 23 nominal, 23 ordinal, 14 discrete, and 20 continuous variables (and 2 additional observation identifiers).
Order (Discrete): Observation number
PID (Nominal): Parcel identification number - can be used with city web site for parcel review.
MS SubClass (Nominal): Identifies the type of dwelling involved in the sale.
020 1-STORY 1946 & NEWER ALL STYLES
030 1-STORY 1945 & OLDER
040 1-STORY W/FINISHED ATTIC ALL AGES
045 1-1/2 STORY - UNFINISHED ALL AGES
050 1-1/2 STORY FINISHED ALL AGES
060 2-STORY 1946 & NEWER
070 2-STORY 1945 & OLDER
075 2-1/2 STORY ALL AGES
080 SPLIT OR MULTI-LEVEL
085 SPLIT FOYER
090 DUPLEX - ALL STYLES AND AGES
120 1-STORY PUD (Planned Unit Development) - 1946 & NEWER
150 1-1/2 STORY PUD - ALL AGES
160 2-STORY PUD - 1946 & NEWER
180 PUD - MULTILEVEL - INCL SPLIT LEV/FOYER
190 2 FAMILY CONVERSION - ALL STYLES AND AGES
MS Zoning (Nominal): Identifies the general zoning classification of the sale.
A Agriculture
C Commercial
FV Floating Village Residential
I Industrial
RH Residential High Density
RL Residential Low Density
RP Residential Low Density Park
RM Residential Medium Density
Lot Frontage (Continuous): Linear feet of street connected to property
Lot Area (Continuous): Lot size in square feet
Street (Nominal): Type of road access to property
Grvl Gravel
Pave Paved
Alley (Nominal): Type of alley access to property
Grvl Gravel
Pave Paved
NA No alley access
Lot Shape (Ordinal): General shape of property
Reg Regular
IR1 Slightly irregular
IR2 Moderately Irregular
IR3 Irregular
Land Contour (Nominal): Flatness of the property
Lvl Near Flat/Level
Bnk Banked - Quick and significant rise from street grade to building
HLS Hillside - Significant slope from side to side
Low Depression
Utilities (Ordinal): Type of utilities available
AllPub All public Utilities (E,G,W,& S)
NoSewr Electricity, Gas, and Water (Septic Tank)
NoSeWa Electricity and Gas Only
ELO Electricity only
Lot Config (Nominal): Lot configuration
Inside Inside lot
Corner Corner lot
CulDSac Cul-de-sac
FR2 Frontage on 2 sides of property
FR3 Frontage on 3 sides of property
Land Slope (Ordinal): Slope of property
Gtl Gentle slope
Mod Moderate Slope
Sev Severe Slope
Neighborhood (Nominal): Physical locations within Ames city limits (map available)
Blmngtn Bloomington Heights
Blueste Bluestem
BrDale Briardale
BrkSide Brookside
ClearCr Clear Creek
CollgCr College Creek
Crawfor Crawford
Edwards Edwards
Gilbert Gilbert
Greens Greens
GrnHill Green Hills
IDOTRR Iowa DOT and Rail Road
Landmrk Landmark
MeadowV Meadow Village
Mitchel Mitchell
Names North Ames
NoRidge Northridge
NPkVill Northpark Villa
NridgHt Northridge Heights
NWAmes Northwest Ames
OldTown Old Town
SWISU South & West of Iowa State University
Sawyer Sawyer
SawyerW Sawyer West
Somerst Somerset
StoneBr Stone Brook
Timber Timberland
Veenker Veenker
Condition 1 (Nominal): Proximity to various conditions
Artery Adjacent to arterial street
Feedr Adjacent to feeder street
Norm Normal
RRNn Within 200' of North-South Railroad
RRAn Adjacent to North-South Railroad
PosN Near positive off-site feature--park, greenbelt, etc.
PosA Adjacent to postive off-site feature
RRNe Within 200' of East-West Railroad
RRAe Adjacent to East-West Railroad
Condition 2 (Nominal): Proximity to various conditions (if more than one is present)
Artery Adjacent to arterial street
Feedr Adjacent to feeder street
Norm Normal
RRNn Within 200' of North-South Railroad
RRAn Adjacent to North-South Railroad
PosN Near positive off-site feature--park, greenbelt, etc.
PosA Adjacent to postive off-site feature
RRNe Within 200' of East-West Railroad
RRAe Adjacent to East-West Railroad
Bldg Type (Nominal): Type of dwelling
1Fam Single-family Detached
2FmCon Two-family Conversion; originally built as one-family dwelling
Duplx Duplex
TwnhsE Townhouse End Unit
TwnhsI Townhouse Inside Unit
House Style (Nominal): Style of dwelling
1Story One story
1.5Fin One and one-half story: 2nd level finished
1.5Unf One and one-half story: 2nd level unfinished
2Story Two story
2.5Fin Two and one-half story: 2nd level finished
2.5Unf Two and one-half story: 2nd level unfinished
SFoyer Split Foyer
SLvl Split Level
Overall Qual (Ordinal): Rates the overall material and finish of the house
10 Very Excellent
9 Excellent
8 Very Good
7 Good
6 Above Average
5 Average
4 Below Average
3 Fair
2 Poor
1 Very Poor
Overall Cond (Ordinal): Rates the overall condition of the house
10 Very Excellent
9 Excellent
8 Very Good
7 Good
6 Above Average
5 Average
4 Below Average
3 Fair
2 Poor
1 Very Poor
Year Built (Discrete): Original construction date
Year Remod/Add (Discrete): Remodel date (same as construction date if no remodeling or additions)
Roof Style (Nominal): Type of roof
Flat Flat
Gable Gable
Gambrel Gabrel (Barn)
Hip Hip
Mansard Mansard
Shed Shed
Roof Matl (Nominal): Roof material
ClyTile Clay or Tile
CompShg Standard (Composite) Shingle
Membran Membrane
Metal Metal
Roll Roll
Tar&Grv Gravel & Tar
WdShake Wood Shakes
WdShngl Wood Shingles
Exterior 1 (Nominal): Exterior covering on house
AsbShng Asbestos Shingles
AsphShn Asphalt Shingles
BrkComm Brick Common
BrkFace Brick Face
CBlock Cinder Block
CemntBd Cement Board
HdBoard Hard Board
ImStucc Imitation Stucco
MetalSd Metal Siding
Other Other
Plywood Plywood
PreCast PreCast
Stone Stone
Stucco Stucco
VinylSd Vinyl Siding
Wd Sdng Wood Siding
WdShing Wood Shingles
Exterior 2 (Nominal): Exterior covering on house (if more than one material)
AsbShng Asbestos Shingles
AsphShn Asphalt Shingles
BrkComm Brick Common
BrkFace Brick Face
CBlock Cinder Block
CemntBd Cement Board
HdBoard Hard Board
ImStucc Imitation Stucco
MetalSd Metal Siding
Other Other
Plywood Plywood
PreCast PreCast
Stone Stone
Stucco Stucco
VinylSd Vinyl Siding
Wd Sdng Wood Siding
WdShing Wood Shingles
Mas Vnr Type (Nominal): Masonry veneer type
BrkCmn Brick Common
BrkFace Brick Face
CBlock Cinder Block
None None
Stone Stone
Mas Vnr Area (Continuous): Masonry veneer area in square feet
Exter Qual (Ordinal): Evaluates the quality of the material on the exterior
Ex Excellent
Gd Good
TA Average/Typical
Fa Fair
Po Poor
Exter Cond (Ordinal): Evaluates the present condition of the material on the exterior
Ex Excellent
Gd Good
TA Average/Typical
Fa Fair
Po Poor
Foundation (Nominal): Type of foundation
BrkTil Brick & Tile
CBlock Cinder Block
PConc Poured Contrete
Slab Slab
Stone Stone
Wood Wood
Bsmt Qual (Ordinal): Evaluates the height of the basement
Ex Excellent (100+ inches)
Gd Good (90-99 inches)
TA Typical (80-89 inches)
Fa Fair (70-79 inches)
Po Poor (<70 inches
NA No Basement
Bsmt Cond (Ordinal): Evaluates the general condition of the basement
Ex Excellent
Gd Good
TA Typical - slight dampness allowed
Fa Fair - dampness or some cracking or settling
Po Poor - Severe cracking, settling, or wetness
NA No Basement
Bsmt Exposure (Ordinal): Refers to walkout or garden level walls
Gd Good Exposure
Av Average Exposure (split levels or foyers typically score average or above)
Mn Mimimum Exposure
No No Exposure
NA No Basement
BsmtFin Type 1 (Ordinal): Rating of basement finished area
GLQ Good Living Quarters
ALQ Average Living Quarters
BLQ Below Average Living Quarters
Rec Average Rec Room
LwQ Low Quality
Unf Unfinshed
NA No Basement
BsmtFin SF 1 (Continuous): Type 1 finished square feet
BsmtFinType 2 (Ordinal): Rating of basement finished area (if multiple types)
GLQ Good Living Quarters
ALQ Average Living Quarters
BLQ Below Average Living Quarters
Rec Average Rec Room
LwQ Low Quality
Unf Unfinshed
NA No Basement
BsmtFin SF 2 (Continuous): Type 2 finished square feet
Bsmt Unf SF (Continuous): Unfinished square feet of basement area
Total Bsmt SF (Continuous): Total square feet of basement area
Heating (Nominal): Type of heating
Floor Floor Furnace
GasA Gas forced warm air furnace
GasW Gas hot water or steam heat
Grav Gravity furnace
OthW Hot water or steam heat other than gas
Wall Wall furnace
HeatingQC (Ordinal): Heating quality and condition
Ex Excellent
Gd Good
TA Average/Typical
Fa Fair
Po Poor
Central Air (Nominal): Central air conditioning
N No
Y Yes
Electrical (Ordinal): Electrical system
SBrkr Standard Circuit Breakers & Romex
FuseA Fuse Box over 60 AMP and all Romex wiring (Average)
FuseF 60 AMP Fuse Box and mostly Romex wiring (Fair)
FuseP 60 AMP Fuse Box and mostly knob & tube wiring (poor)
Mix Mixed
1st Flr SF (Continuous): First Floor square feet
2nd Flr SF (Continuous) : Second floor square feet
Low Qual Fin SF (Continuous): Low quality finished square feet (all floors)
Gr Liv Area (Continuous): Above grade (ground) living area square feet
Bsmt Full Bath (Discrete): Basement full bathrooms
Bsmt Half Bath (Discrete): Basement half bathrooms
Full Bath (Discrete): Full bathrooms above grade
Half Bath (Discrete): Half baths above grade
Bedroom (Discrete): Bedrooms above grade (does NOT include basement bedrooms)
Kitchen (Discrete): Kitchens above grade
KitchenQual (Ordinal): Kitchen quality
Ex Excellent
Gd Good
TA Typical/Average
Fa Fair
Po Poor
TotRmsAbvGrd (Discrete): Total rooms above grade (does not include bathrooms)
Functional (Ordinal): Home functionality (Assume typical unless deductions are warranted)
Typ Typical Functionality
Min1 Minor Deductions 1
Min2 Minor Deductions 2
Mod Moderate Deductions
Maj1 Major Deductions 1
Maj2 Major Deductions 2
Sev Severely Damaged
Sal Salvage only
Fireplaces (Discrete): Number of fireplaces
FireplaceQu (Ordinal): Fireplace quality
Ex Excellent - Exceptional Masonry Fireplace
Gd Good - Masonry Fireplace in main level
TA Average - Prefabricated Fireplace in main living area or Masonry Fireplace in basement
Fa Fair - Prefabricated Fireplace in basement
Po Poor - Ben Franklin Stove
NA No Fireplace
Garage Type (Nominal): Garage location
2Types More than one type of garage
Attchd Attached to home
Basment Basement Garage
BuiltIn Built-In (Garage part of house - typically has room above garage)
CarPort Car Port
Detchd Detached from home
NA No Garage
Garage Yr Blt (Discrete): Year garage was built
Garage Finish (Ordinal) : Interior finish of the garage
Fin Finished
RFn Rough Finished
Unf Unfinished
NA No Garage
Garage Cars (Discrete): Size of garage in car capacity
Garage Area (Continuous): Size of garage in square feet
Garage Qual (Ordinal): Garage quality
Ex Excellent
Gd Good
TA Typical/Average
Fa Fair
Po Poor
NA No Garage
Garage Cond (Ordinal): Garage condition
Ex Excellent
Gd Good
TA Typical/Average
Fa Fair
Po Poor
NA No Garage
Paved Drive (Ordinal): Paved driveway
Y Paved
P Partial Pavement
N Dirt/Gravel
Wood Deck SF (Continuous): Wood deck area in square feet
Open Porch SF (Continuous): Open porch area in square feet
Enclosed Porch (Continuous): Enclosed porch area in square feet
3-Ssn Porch (Continuous): Three season porch area in square feet
Screen Porch (Continuous): Screen porch area in square feet
Pool Area (Continuous): Pool area in square feet
Pool QC (Ordinal): Pool quality
Ex Excellent
Gd Good
TA Average/Typical
Fa Fair
NA No Pool
Fence (Ordinal): Fence quality
GdPrv Good Privacy
MnPrv Minimum Privacy
GdWo Good Wood
MnWw Minimum Wood/Wire
NA No Fence
Misc Feature (Nominal): Miscellaneous feature not covered in other categories
Elev Elevator
Gar2 2nd Garage (if not described in garage section)
Othr Other
Shed Shed (over 100 SF)
TenC Tennis Court
NA None
Misc Val (Continuous): $Value of miscellaneous feature
Mo Sold (Discrete): Month Sold (MM)
Yr Sold (Discrete): Year Sold (YYYY)
Sale Type (Nominal): Type of sale
WD Warranty Deed - Conventional
CWD Warranty Deed - Cash
VWD Warranty Deed - VA Loan
New Home just constructed and sold
COD Court Officer Deed/Estate
Con Contract 15% Down payment regular terms
ConLw Contract Low Down payment and low interest
ConLI Contract Low Interest
ConLD Contract Low Down
Oth Other
Sale Condition (Nominal): Condition of sale
Normal Normal Sale
Abnorml Abnormal Sale - trade, foreclosure, short sale
AdjLand Adjoining Land Purchase
Alloca Allocation - two linked properties with separate deeds, typically condo with a garage unit
Family Sale between family members
Partial Home was not completed when last assessed (associated with New Homes)
SalePrice (Continuous): Sale price $$
SPECIAL NOTES:
There are 5 observations that an instructor may wish to remove from the data set before giving it to students (a plot of SALE PRICE versus GR LIV AREA will indicate them quickly). Three of them are true outliers (Partial Sales that likely don�t represent actual market values) and two of them are simply unusual sales (very large houses priced relatively appropriately). I would recommend removing any houses with more than 4000 square feet from the data set (which eliminates these 5 unusual observations) before assigning it to students.
STORY BEHIND THE DATA:
This data set was constructed for the purpose of an end of semester project for an undergraduate regression course. The original data (obtained directly from the Ames Assessor�s Office) is used for tax assessment purposes but lends itself directly to the prediction of home selling prices. The type of information contained in the data is similar to what a typical home buyer would want to know before making a purchase and students should find most variables straightforward and understandable.
PEDAGOGICAL NOTES:
Instructors unfamiliar with multiple regression may wish to use this data set in conjunction with an earlier JSE paper that reviews most of the major issues found in regression modeling:
Kuiper , S. (2008), �Introduction to Multiple Regression: How Much Is Your Car Worth?�, Journal of Statistics Education Volume 16, Number 3 (2008).
Outside of the general issues associated with multiple regression discussed in this article, this particular data set offers several opportunities to discuss how the purpose of a model might affect the type of modeling done. User of this data may also want to review another JSE article related directly to real estate pricing:
Pardoe , I. (2008), �Modeling home prices using realtor data�, Journal of Statistics Education Volume 16, Number 2 (2008).
One issue is in regards to homoscedasticity and assumption violations. The graph included in the article appears to indicate heteroscedasticity with variation increasing with sale price and this problem is evident in many simple home pricing models that focus only on house and lot sizes. Though this violation can be alleviated by transforming the response variable (sale price), the resulting equation yields difficult to interpret fitted values (selling price in log or square root dollars). This situation gives the instructor the opportunity to talk about the costs (biased estimators, incorrect statistical tests, etc.) and benefits (ease of use) of not correcting this assumption violation. If the purpose in building the model is simply to allow a typical buyer or real estate agent to sit down and estimate the selling price of a house, such transformations may be unnecessary or inappropriate for the task at hand. This issue could also open into a discussion on the contrasts and comparisons between data mining, predictive models, and formal statistical inference.
A second issue closely related to the intended use of the model, is the handling of outliers and unusual observations. In general, I instruct my students to never throw away data points simply because they do not match a priori expectations (or other data points). I strongly make this point in the situation where data are being analyzed for research purposes that will be shared with a larger audience. Alternatively, if the purpose is to once again create a common use model to estimate a �typical� sale, it is in the modeler�s best interest to remove any observations that do not seem typical (such as foreclosures or family sales).
REFERENCES:
Individual homes within the data set can be referenced directly from the Ames City Assessor webpage via the Parcel ID (PID) found in the data set. Note these are nominal values (non-numeric) so preceding 0�s must be included in the data entry field on the website. Access to the database can be gained from the Ames site (http://www.cityofames.org/assessor/) by clicking on �property search� or by accessing the Beacon (http://beacon.schneidercorp.com/Default.aspx) website and inputting Iowa and Ames in the appropriate fields. A city map showing the location of all the neighborhoods is also available on the Ames site and can be accessed by clicking on �Maps� and then �Residential Assessment Neighborhoods (City of Ames Only)�.
SUBMITTED BY:
Dean De Cock
Truman State University
100 E. Normal St., Kirksville, MO, 63501
[email protected]
