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 decock@truman.edu