ECO GUIDE TO Unstratified Samples

Transcription

1 ECO GUIDE TO Unstrtifid Smpls Wht Is n Unstrtifid Smpld? If you hv didd to ondut smpl invntory, you will b ollting dt for plots lotd throughout your study r. In this typ of projt, you n hoos to strtify or subdivid your study r into smllr units tht n hlp lrify diffrns ross th study r. For xmpl, you might strtify your study r by lnd us, nighborhood, or politil boundris so tht you n ompr urbn forst ffts in diffrnt strt. With n unstrtifid smpl, you hv hosn not to subdivid th study r nd your Eo rsults will b stimtd for th ntir study r only. This is simplr mthod nd offrs th dvntg of tru rndomnss. Howvr, th dision to strtify should ultimtly b bsd on your urrnt nd futur projt objtivs nd vilbl rsours. Tip Th dirtions in this guid ssum tht you hv lrdy dsignd nd rtd your Eo projt s dsribd in th Usr s Mnul. S th Usr s Mnul for hlp if you hv not ompltd ths stps. Unstrtifid Smpl Mthods Thr r svrl ommon smpl rtion mthods tht you n us whn you rt your smpl. In this guid w will dsrib th thr mthods tht r inludd in th Eo pplition. Th following mthods r dsribd for unstrtifid smpl projts in whih you rt smpl of plots by rndomly pling thm ross th study r: Lod from Fil Crt smpl of plots nd thn import th plot list into Eo. This stion inluds dirtions for rting your plot smpl in ESRI s ArGIS, formtting th nssry fils for Eo, nd importing th fils using th Lod from Fil funtion. vi Googl Mps Crt smpl of plots dirtly in th Eo pplition using th rndom plots gnrtor in th vi Googl Mps funtion. Pg

2 Usr Dfind Mnully dfin th plot siz nd numbr of plots in your study r using th Usr Dfind funtion. Thr r mny wys to rt your plot smpl. Your dision should b bsd on th objtivs of your study nd th rsours vilbl to rt th lyout. You n us ny mthod you lik to rt your smpl, inluding ppr mps nd pnil, s long s it follows rndom smpling onvntions. Tip Som Eo usrs ollbort with lol univrsitis or govrnmnt gnis for ssistn to rt rndom plot lyouts for thir projts. Lod from Fil i-tr Eo offrs two-stp mthod for dfining your smpl plots outsid of th pplition, nd thn importing th plot dt into Eo. First, rt your rndom smpl using ArGIS s dsribd blow. Sond, import your fil list using th Lod from Fil funtion in th Eo pplition. Crting Rndom Smpl in ArGIS Ths instrutions will hlp usrs of ll skill lvls rt rndom smpl of i-tr Eo plot ntrs, plot rs, nd th ssoitd i-tr Eo-rquird dt fils for thir study r. Th stps blow r bsd on ESRI ArGIS softwr with th Sptil Anlyst xtnsion. Howvr, th instrutions r gnri nd n b modifid to suit diffrnt vrsions of ArGIS s wll s othr GIS softwr in trms of bsi oprtions. Ths instrutions involv thr bsi stps: 1 Prpr projt r dt. 2 Gnrt smpl plots. 3 Crt Eo-rdy output. Whn finishd, you will hv rtd th following: Ar-of-intrst (AOI) mp lyr omposd of singl (or multi-prt) polygon. Rndom smpl plot ntrs point mp lyr with Eo-rquird filds ddd nd popultd. Smpl plot rs polygon mp lyr. Pg 2

3 Eo-rdy Strt Ar txt fil. Eo-rdy Plot List txt fil. Eo-rdy Projtion prj fil. Tips Th Sptil Anlyst xtnsion for ArGIS is rquird. Fild nms nd typs r importnt. Obtin projtion systm nd mp unit informtion from th mp dt providr first. All mp dt must hv vlid projtion informtion for propr lignmnt. AOI mp dt must b in projtion systm tht uss ft or mtrs not dgrs. Finl Eo-rquird mp units will b mtri. AOI xmpls r polygons,.g., ity boundry, prk rs, or mngmnt zons. ESRI shpfils r sist to us. Pin opn ArToolbox whn strting pushpin ion, uppr right of ArToolbox pnl. Prti good fil mngmnt: Crt foldrs to hold opis of originl dt, foldrs to hold output, mploy logil fil nming, t. ArGIS should dd th goprossd mp lyrs to th viw utomtilly. If not, us th Fil > Add Dt > Add Dt mnu to lod th lyrs. STEP 1: Prpr projt r dt Ovrviw Obtin GIS mp lyr rprsnting th r-of-intrst (AOI) polygon(s) for your projt r. Lunh th ArMp pplition of ArGIS. Lod th AOI mp lyr into th dt viw. Dfin th projtion/oordint systm of th AOI if ndd. Rprojt th AOI to systm using ft or mtrs if ndd. Dissolv th AOI into singl polygon ( singl, multi-prt polygon if mor thn on polygon). Add Eo-rquird filds nd lult pproprit vlus for thm. Dtild instrutions 1 Obtin n r-of-intrst (AOI) polygon from your GIS Dprtmnt or n onlin rsour. Svrl options n b found hr: 2 Lunh ArMp. Sv your projt with n pproprit nm t nw lotion vi th Fil > Sv As mnu. Sv priodilly whil working to void dt loss. Pg 3

4 3 Us th Fil > Add Dt > Add Dt mnu to brows to nd lod th AOI polygon mp lyr to th urrnt viw. If your dt r proprly projtd, ArGIS should hndl projtion diffrns btwn th AOI nd subsqunt mp lyrs on th fly. b If your dt lk projtion informtion, n Unknown Sptil Rfrn mssg my ppr. Clik OK to mov pst it nd us ArToolbox to dfin th projtion of th AOI mp lyr ording to your dt providr s spifitions. 4 Nvigt to ArToolbox > Dt Mngmnt Tools > Projtions nd Trnsformtions > Dfin Projtion nd omplt th Dfin Projtion form s follows: For Input Dtst, hoos th AOI mp lyr from th drop-down list. b For Coordint Systm, lik th Proprtis button to th right. In th Sptil Rfrn Proprtis window tht pprs, lik Slt nd hoos th oordint systm inditd by your dt providr. 5 If nssry, us ArToolbox to rprojt your AOI mp lyr to systm using ft or mtrs, idlly slting projtion systm lrdy in us by your orgniztion or ommonly usd systm,.g., Stt Pln or UTM in th Unitd Stts. 6 Nvigt to ArToolbox > Dt Mngmnt Tools > Projtions nd Trnsformtions > Ftur > Projt nd omplt th Projt form s follows: For Input Dtst, slt th AOI mp lyr from th drop-down mnu. b Input Coordint Systm should b gryd out bsd on your work in th prvious stp or pr your dt providr. For Output Dtst or Ftur Clss, us th Brows button to th right nd nvigt to suitbl lotion to sv th output fil nd giv it nm. d For Output Coordint Systm, lik th Proprtis button to th right. f In th Sptil Rfrn Proprtis window tht pprs, lik th Slt button nd nvigt to th propr oordint systm. For Gogrphi Trnsformtion, slt th first hoi in th drop-down list if promptd with n Undfind Gogrphi Trnsformtion mssg. Pg 4

5 g Clik OK whn you v ompltd ll th boxs. 7 If your AOI hs mor thn on polygon, you must us ArToolbox to dissolv thm. (If not, skip to #8 blow.) Nvigt to ArToolbox > Dt Mngmnt Tools > Gnrliztion > Dissolv nd omplt th Dissolv form s follows: b For Input Fturs, slt th projtd AOI mp lyr from th list. For Output Ftur Clss, us th Brows button to nvigt to suitbl lotion nd giv th fil nm. d For Dissolv Fild, hk th dt fild ttribut vlu tht unifis th AOI. (For xmpl, Nm fild ontining th ity nm of n AOI, vn ross physilly sprt ity stions.) You my nd to prus th lyr s ttribut tbl to find this. f Lv th Sttistis fild blnk. Ensur th Crt Multiprt Fturs box is hkd. g Clik OK to finish. 8 Right-lik th nw dissolvd AOI polygon lyr, Opn Attribut Tbl nd vrify tht thr is now singl, multiprt polygon prsnt. 9 Us ArToolbox to dd Eo-rquird filds to th projtd, dissolvd AOI mp lyr: Nvigt to ArToolbox > Dt Mngmnt Tools > Filds > Add Fild nd omplt th Add Fild form s follows: b Undr Input Tbl, slt th dissolvd AOI mp lyr from th dropdown list. For Fild Nm, ntr Strt_ID d For Fild Typ, slt LONG from th drop-down list. Skip th following filds: Fild Prision Fild Sl Fild Lngth Fild Alis Fild is Nullbl Pg 5

6 Fild is Rquird Fild Domin f Clik OK. 10 Rpt th stps bov s follows for ths dditionl filds: For Fild Nm, ntr Strt_Ar nd slt DOUBLE from th Fild Typ drop-down list. b For Fild Nm, ntr Strt nd slt TEXT from th Fild Typ drop-down list. 11 Us th ttribut tbl Fild Clultor to popult vlus for th Eo-spifi filds ddd to th projtd, dissolvd AOI mp lyr: Right-lik th projtd, dissolvd AOI mp lyr nd slt Opn Attribut Tbl. b Right-lik th Strt_ID fild olumn hding nd slt Fild Clultor. In th lrg txt ntry box blow Strt_ID =, ntr: 1. d Clik OK. f Rpt for th Strt fild. In th lrg txt ntry box blow Strt =, ntr: Singl Strt (Not: In this s, inlud th quots!) g Clik OK. h Right-lik th Strt_Ar fild olumn hding nd slt Clult Gomtry. i j k l For Proprty, hoos Slt Ar. If this is not vilbl, your AOI mp lyr is not in projtion systm using ft or mtrs; s Stps 4 nd 5. For Coordint Systm, hoos Us oordint systm of th dt sour. For Units, slt Htrs [h]. Clos th Attribut Tbl whn finishd. Pg 6

7 Rsults An r-of-intrst (AOI) singl polygon mp lyr with Eo-rquird filds ddd nd popultd. Th AOI polygon mp lyr is now rdy to b usd for plot gnrtion. STEP 2: Gnrt smpl plots Ovrviw Run th Crt Rndom Points tool from ArToolbox for th AOI. Add Eo-rquird filds to th rndom plots dt. Clult fild vlus for th rndom plots dt. Buffr th rndom plots point dt to form plot rs. Dtild instrutions Us th Crt Rndom Points tool in ArToolbox to gnrt th dsird numbr of plots for th projtd, dissolvd AOI. 1 Nvigt to ArToolbox > Dt Mngmnt Tools > Ftur Clss > Crt Rndom Points. 2 Complt th Crt Rndom Points form: For Output Lotion, brows to your working foldr, singl-lik to slt it, nd lik Add. b For Output Point Ftur Clss, typ in n pproprit nm with.shp xtnsion. For Constrining Ftur Clss, slt your projtd, dissolvd AOI polygon mp lyr. d For Numbr of Points [vlu or fild], ntr th dsird numbr of smpl plots for this sltd lnd ovr. f Skip th rmining inputs. Clik OK. Us ArToolbox to dd Eo-rquird filds to th nwly rtd smpl plots point mp lyr. 1 Nvigt to ArToolbox > Dt Mngmnt Tools > Filds > Add Fild. Pg 7

8 2 Complt th Add Fild form: For Input Tbl, slt th nwly rtd smpl plots point mp lyr from th drop-down list. b For Fild Nm, ntr: ID For Fild Typ, slt LONG from th drop-down list. d Skip th following filds: Fild Prision Fild Sl Fild Lngth Fild Alis Fild is Nullbl Fild is Rquird Fild Domin Clik OK. 3 Rpt th stps bov s follows for ths dditionl filds: For Fild Nm, ntr LCCod nd slt SHORT from th Fild Typ dropdown list. b For Fild Nm, ntr X_Coord nd slt DOUBLE from th Fild Typ drop-down list. For Fild Nm, ntr Y_Coord nd slt DOUBLE from th Fild Typ drop-down list. Us th ttribut tbl Fild Clultor to popult vlus for th Eo-spifi filds ddd to th smpl plots point mp lyr in th stp bov. 1 Right-lik th smpl plots point mp lyr nd slt Opn Attribut Tbl. 2 Right-lik th ID fild olumn hding nd slt Fild Clultor. In th lrg txt ntry box blow ID =, ntr: [FID]+1 b Clik OK. 3 Rpt stp 2 for th LCCod fild. Pg 8

9 In th lrg txt ntry box blow LCCod =, ntr: 1 4 Right-lik th X_Coord fild olumn hding nd slt Clult Gomtry. For Proprty, slt X Coordint of Point. b For Coordint Systm, hoos Us oordint systm of th dt sour. For Units, slt Mtrs [m]. d Clik OK. 5 Right-lik th Y_Coord fild olumn hding nd slt Clult Gomtry. For Proprty, slt Y Coordint of Point. b For Coordint Systm hoos Us oordint systm of th dt sour. For Units, slt Mtrs [m]. d Clik OK. 6 To vrify th ttributs hv bn orrtly modifid in th smpl plots point mp lyr, right-lik th smpl plots point mp lyr in th mp lyrs list, nd hoos Opn Attribut Tbl. Sn through th filds nd thir vlus to vrify thy r orrt. Optionl: Us ArToolbox to buffr th smpl plots point mp lyr. This pross rts th plot of your dsird survy siz round th plot ntrs nd n b usd to mk fild dt olltion plot mps. 1 Nvigt to ArToolbox > Anlysis Tools > Proximity > Buffr. 2 Complt th Buffr form: Undr Input Fturs, slt th smpl plots point mp lyr from th dropdown list. b For Output Ftur Clss, us th Brows button to nvigt to suitbl lotion nd hoos fil nm for th rsulting mp lyr. For Distn, in th Linr Unit box, ntr th distn vlu from th list blow, bsd on your dsird plot siz. (Th distn is th rdius of th plot.) Pg 9

10 Ft: For 1/5-r plots, ntr: For 1/10-r plots, ntr: For 1/20-r plots, ntr: For 1/100-r plots, ntr: Mtrs: For 1/5-htr plots, ntr: For 1/10-htr plots, ntr: For 1/20-htr plots, ntr: For 1/100-htr plots, ntr: 5.64 d Slt Ft or Mtrs s pproprit from th units drop-down list. f Skip th following ntris: Sid Typ End Typ Dissolv Typ Dissolv Fild(s) Clik OK. 3 Th buffrd smpl points lyr is ddd to th mp viw utomtilly; zoom in to xmin individul plot rs. (Not: Choos n pproprit qul-r projtion systm in th lyrs dt viw proprtis if your plot rs ppr not to b irulr.) Rsults Smpl plots point mp lyr. Usr-dfind numbr of plots rndomly sprd throughout th AOI. Plot points ssignd with lnd ovr tgoris. Eo-rquird filds ddd nd popultd. Smpl plot rs polygon mp lyr (optionl). STEP 3: Crt Eo-rdy output Ovrviw Export slt filds from th Plot ttribut tbl to txt fil. Export slt filds from th Strt polygons ttribut tbl to txt fil. Copy nd rnm th AOI projtion fil. Pg 10

11 Dtild instrutions 1 From th Sltion mnu, hoos Clr Sltd Fturs, if vilbl, to unslt ll fturs. 2 Right-lik th sptilly joind smpl plot ntrs point mp lyr in th mp lyrs list nd slt Opn Attribut Tbl. Right-lik th FID fild nd slt Turn Fild Off. b Rpt for ll but th ID, LCCod, X_Coord, nd Y_Coord filds (ddd in Smpl Plot Gnrtion bov). Undr th uppr lft Tbl Options drop-down button, slt Export. d Brows to foldr whr you wish to sv th output fil. f For Sv th fil s typ, slt Txt Fil. Nm th xport ppropritly,.g., myeoplots_mmyyyy.txt. g Clik No whn skd whthr to dd th nw tbl to th urrnt mp. 3 Opn th txt fil in simpl ditor,.g., Windows Notpd (void using word prossing softwr du to formtting issus). Us th Srh nd Rpl funtion to rpl h omm with sp. b Sv th fil. Dlt th first lin ontining ths fild nms: ID, LCCod, X_ Coord, Y_Coord. d Copy nd pst ths two lins t th top of th fil: $ U4PLLS! A proprly formttd fil will look lik this: $U4PLLS! Pg 11

12 ... 4 Right-lik th dissolvd lnd ovr polygon lyr in th mp lyrs list nd slt Opn Attribut Tbl. Right-lik th FID fild nd slt Turn Fild Off. b Rpt for ll but th Strt_ID, Strt_Ar, nd Strt filds (ddd in Strt Prprtion bov). Undr th Tbl Options drop-down button, slt Export. d Brows to foldr whr you wish to sv th output fil nd sv s txt fil. f Nm th xport ppropritly,.g., myeostrt_mmyyyy.txt. Clik No whn skd whthr to dd th nw tbl to th urrnt mp. 5 Opn th txt fil in simpl ditor (void using word prossing softwr). Us th Srh nd Rpl funtion to rpl h omm with sp. b Sv th fil. Dlt th first lin ontining ths fild nms: Strt_ID, Strt_ Ar, Strt d Copy nd pst ths two lins t th top of th fil: $U4STAR! A proprly formttd fil will look lik this: $U4STAR! Dvlopd Opn Othr... 6 Mk opy of th.prj fil ssoitd with your dissolvd lnd ovr polygons lyr. In Windows Explorr, brows to your working foldr nd opy/pst th.prj fil ssoitd with this shpfil. Pg 12

13 b Right-lik th opid fil, nd Rnm it ppropritly,.g., myeoprojtion_mmddyyyy.prj. Rsults Thr Eo-rdy fils: Plot List Fil (txt formt). Strt Fil (txt formt). GIS Projtion Fil (prj formt utomtilly rtd in th Dfin Projtion/Rprojtion stps bov s prt of th STEP 1: Prpr projt r dt stion). Importing Plot Fils in i-tr Eo In th Projt Configurtion tb of th Eo dsktop pplition, lik on th Lod from Fil funtion of th Dfin Plots group. 1 Clik on th Brows button nxt to th Plot List Fil box. 2 Nvigt to th plot list fil tht you prviously rtd nd lik Opn. This fil must b in txt formt. 3 Clik on th Brows button nxt to th Strt Fil box. 4 Nvigt to th strt fil tht you prviously rtd nd lik Opn. This fil must b in txt formt. 5 Clik on th Brows button nxt to th GIS Projtion Fil box. 6 Nvigt to th GIS projtion fil tht you prviously rtd nd lik Opn. This fil must b in prj formt. 7 Clik Import. vi Googl Mps i-tr Eo offrs rndom plot gnrtor tht llows you to rt your smpl right in th pplition itslf. Th plot gnrtor works with Googl Mps nd utilizs study r boundris tht n b drwn by th usr or supplid from n ESRI ArGIS shpfil. This mthod n b usd whthr you hv didd to strtify your smpl or not. Howvr, in th Googl Mps Plot Gnrtor, plots r distributd rndomly nd nnot b distributd on fixd grid or rndomizd grid. Pg 13

14 In th Projt Configurtion tb of th Eo dsktop pplition, lik on th vi Googl Mps funtion of th Dfin Plots group. To prpr n unstrtifid plot lyout, you will b hoosing on of th Simpl rndom options. For this option, you must first dfin th boundris of your study r ithr by providing GIS shpfil of th boundry or drwing th boundry in Googl Mps. Simpl Rndom (Shpfil Boundry) Us this option if you lrdy hv GIS shpfil boundry dfind for your r of intrst. All of your plots will b rndomly distributd within tht boundry. Simpl rndom smpling will gnrt plot lotions s rndom sts of ltitud nd longitud oordints within your boundry. This is th most bsi typ of smpling nd is pproprit for most projts fousd on summris for your ntir r of intrst. 1 Hv n ESRI ArGIS shpfil of th boundry of your projt r rdy. You must hv th shp, dbf, nd shx fils ssoitd with this boundry nd th shpfil must b in gogrphi projtion (ltitud/longitud). 2 Slt Simpl rndom (shpfil boundry) nxt to Options. 3 Clik on th Brows buttons nxt to h of th shpfils boxs in turn. 4 For h shpfil box, nvigt to th GIS shpfil tht you hv nd lik Opn. (Not: Th shpfils tht you ntr must b in shp, dbf, nd shx formts. B sur to slt th pproprit formt for h ntry.) 5 Clik on th Prod to rndom plot gnrtion button. 6 Confirm tht you wnt to rt simpl rndom smpl (i.., unstrtifid plot lyout) using shpfil boundry by liking OK in th mssg tht pops up. 7 Indit how lrg your smpl plots should b by lving th 0.1 rs or htrs (stndrd plot siz) sltd or ntring ustom plot siz or rdius in th box providd. (Not: If you r ntring ustom plot siz, b sur to look t th units displyd nd ntr vlu tht orrsponds to thos units.) 8 Indit how mny smpl plots to rt by ntring numbr of plots or prnt of th projt r tht you would lik to smpl in th boxs providd. Pg 14

15 (Not: Th projt r bsd on your study r boundry pprs blow th Googl Mps disply.) 9 Clik on th Gnrt rndom smpl plots button. 10 Clik OK. Simpl Rndom (Usr Drwn Boundry) Us this option if you do not hv GIS shpfil dfining th boundry of your r of intrst. You will drw your boundry using Googl Mps. All of your plots will b rndomly distributd within tht boundry. Simpl rndom smpling will gnrt plot lotions s rndom sts of ltitud nd longitud oordints within your boundry. This is th most bsi typ of smpling nd is pproprit for most projts fousd on summris for your ntir r of intrst. 1 Slt th Simpl rndom (usr drwn boundry) nxt to Options. 2 Clik on th Prod to rndom plot gnrtion button. 3 Entr th pproximt lotion of your study r (.g., ity nd stt) in th sp providd nd lik Go. Th mp in th Googl Mp disply should zoom to tht lotion. 4 Us th nvigtion nd zoom tools on th lft-hnd sid of th mp disply to djust th viw of your study r. 5 Us th Mp nd Stllit buttons t th top of th mp disply to toggl thos displys on nd off. 6 To drw your boundry, lik on th Drw polygon tool lotd bov th uppr lfthnd ornr of th mp disply. Whil this tool is tiv, lik on th mp to strt drwing your boundry. b Clik t h lotion whr you would lik to dd point to your boundry. Doubl-lik to finish th drwing. 7 To dlt boundry tht you hv drwn, lik on th polygon to slt it nd thn right-lik on th polygon. Clik on th X button tht pprs. 8 Whn you hv boundry tht you r stisfid with, lik on th Don nd Continu button. Pg 15

16 9 Indit how lrg your smpl plots should b by lving th 0.1 rs or htrs (stndrd plot siz) sltd or ntring ustom plot siz or rdius in th box providd. (Not: If you r ntring ustom plot siz, b sur to look t th units displyd nd ntr vlu tht orrsponds to thos units.) 10 Indit how mny smpl plots to rt by ntring numbr of plots or prnt of th projt r tht you would lik to smpl in th boxs providd. (Not: Th projt r bsd on your study r boundry is displyd blow th Googl Mps disply.) 11 Clik on th Gnrt rndom smpl plots button. 12 Clik OK. Usr Dfind i-tr Eo offrs mthod for dfining your smpl plots mnully in th pplition. In th Projt Configurtion tb of th Eo dsktop pplition, lik on th Usr Dfind funtion of th Dfin Plots group. 1 Entr th siz of your smpl plots in th box providd bov th tbl. (Not: Mk not of th units i.., rs or htrs shown nxt to th Nw Plot Ar box nd b sur tht th plot siz you ntr orrsponds with th units listd.) 2 Entr th numbr of plots to b ddd to your study r in th olumn lbld Plots to Add. (Not: Th dfult strtum for nw Eo projts is urbn. Usrs my hng th Strt Dsription, Strt Abbrvition, nd Ar in both th Usr Dfind nd Projt & Strt Ar funtions in th Projt Configurtion tb. For n unstrtifid smpl, only on strtum should b dfind nd it should nompss th ntir study r.) 3 Whn you r stisfid with your strt nd plots, lik OK in th top right-hnd ornr of th tion pnl. This will sv th dits tht you hv md to th tbl. 4 Clik Cnl if you did to rvrt to ll of th prvious vlus, whthr dfult vlus or thos tht you hd prviously ntrd mnully. Pg 16

17 Adding Plots Whn you pln your i-tr Eo projt, on of th disions tht you mk rly on is how mny plots should b inludd in your plot smpl. Whil this dision should b bsd on your projt gols, w do rommnd tht you dd n xtr 5-10% to your finl numbr of plots. Ths xtr plots n srv s rplmnts whr nothr plot is inssibl. For xmpl, lt s sy tht you hv strtd nw projt in Eo nd dfind your plots for your unstrtifid smpl using on of th mthods outlind bov (Lod from Fil, vi Googl Mps, or Usr Dfind). Dspit th bst plnning fforts, you my find yourslf in position whr you nd to dd mor plots to your smpl. Th simplst wy to do this is using th Usr Dfind funtion s dsribd bov. Pg 17