Twaweza: Addressing common concerns raised about our opinion poll survey

[Informer]

Much of the discussion in traditional media, on social media and elsewhere regarding our recently published opinion poll findings on Tanzanian politics has focussed on perceived errors in the brief. We want to correct three of the most common misunderstandings.


1. "Totals do not add up to 100%."

It has been pointed out that several charts and tables in the brief include data that does not seem to add up to 100%. In some cases, the figures add up to 99%, 101% or 102%.

This is purely as a result of rounding the figures to the nearest whole number, a standard practice in opinion poll research. We do this because presenting figures with one or even two decimal points suggests a level of precision in the findings that can be misleading.

The examples below show how this happens, by presenting the unrounded figures alongside the rounded figures that were presented in the brief.

For Figure 2a: Are you aware of the promises made by your MP?
[TABLE="width: 289"]
[TR]
[TD][/TD]
[TD]

unrounded​

[/TD]
[TD]

rounded​

[/TD]
[/TR]
[TR]
[TD] Don't know[/TD]
[TD]

5.14%​

[/TD]
[TD]

5%​

[/TD]
[/TR]
[TR]
[TD] Yes[/TD]
[TD]

64.39%​

[/TD]
[TD]

64%​

[/TD]
[/TR]
[TR]
[TD] No[/TD]
[TD]

30.47%​

[/TD]
[TD]

30%​

[/TD]
[/TR]
[TR]
[TD] Total[/TD]
[TD]

100.00%​

[/TD]
[TD]

99%​

[/TD]
[/TR]
[/TABLE]

For Figures 5b, 5c, 5d: If the election was held today, which political party's candidate would you vote for? / Which political party do you feel closest to, if any?
[TABLE="width: 633"]
[TR]
[TD][/TD]
[TD="colspan: 2"]

2015 MP (Figure 5b)​

[/TD]
[TD="colspan: 2"]

2015 councillor (Figure 5c)​

[/TD]
[TD="colspan: 2"]

2015 affiliation (Figure 5d)​

[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]

unrounded​

[/TD]
[TD]

rounded​

[/TD]
[TD]

unrounded​

[/TD]
[TD]

rounded​

[/TD]
[TD]

unrounded​

[/TD]
[TD]

rounded​

[/TD]
[/TR]
[TR]
[TD] CCM[/TD]
[TD]

60.4%​

[/TD]
[TD]

60%​

[/TD]
[TD]

59.9%​

[/TD]
[TD]

60%​

[/TD]
[TD]

61.9%​

[/TD]
[TD]

62%​

[/TD]
[/TR]
[TR]
[TD] Chadema[/TD]
[TD]

24.1%​

[/TD]
[TD]

24%​

[/TD]
[TD]

25.5%​

[/TD]
[TD]

26%​

[/TD]
[TD]

25.0%​

[/TD]
[TD]

25%​

[/TD]
[/TR]
[TR]
[TD] CUF[/TD]
[TD]

1.8%​

[/TD]
[TD]

2%​

[/TD]
[TD]

2.5%​

[/TD]
[TD]

3%​

[/TD]
[TD]

2.3%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] ACT-Wazalendo[/TD]
[TD]

1.4%​

[/TD]
[TD]

1%​

[/TD]
[TD]

0.6%​

[/TD]
[TD]

1%​

[/TD]
[TD]

0.7%​

[/TD]
[TD]

1%​

[/TD]
[/TR]
[TR]
[TD] NCCR Mageuzi[/TD]
[TD]

1.1%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1.0%​

[/TD]
[TD]

1%​

[/TD]
[TD]

0.3%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] Ukawa*[/TD]
[TD]

2.8%​

[/TD]
[TD]

3%​

[/TD]
[TD]

2.6%​

[/TD]
[TD]

3%​

[/TD]
[TD]

2.1%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] Other[/TD]
[TD]

6.4%​

[/TD]
[TD]

6%​

[/TD]
[TD]

6.0%​

[/TD]
[TD]

6%​

[/TD]
[TD]

2.3%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] Don't know / no response[/TD]
[TD]

2.0%​

[/TD]
[TD]

2%​

[/TD]
[TD]

1.9%​

[/TD]
[TD]

2%​

[/TD]
[TD]

5.3%​

[/TD]
[TD]

5%​

[/TD]
[/TR]
[TR]
[TD] Total[/TD]
[TD]

100.0%​

[/TD]
[TD]

99%​

[/TD]
[TD]

100.0%​

[/TD]
[TD]

102%​

[/TD]
[TD]

100.0%​

[/TD]
[TD]

99%​

[/TD]
[/TR]
[/TABLE]

For Figure 6b: Will Ukawa appear on the ballot paper during the 2015 elections?
[TABLE="width: 289"]
[TR]
[TD][/TD]
[TD] unrounded[/TD]
[TD] rounded[/TD]
[/TR]
[TR]
[TD] Don't know[/TD]
[TD]

17.6%​

[/TD]
[TD]

18%​

[/TD]
[/TR]
[TR]
[TD] No[/TD]
[TD]

25.7%​

[/TD]
[TD]

26%​

[/TD]
[/TR]
[TR]
[TD] Yes[/TD]
[TD]

56.7%​

[/TD]
[TD]

57%​

[/TD]
[/TR]
[TR]
[TD] Total[/TD]
[TD]

100.0%​

[/TD]
[TD]

101%​

[/TD]
[/TR]
[/TABLE]


2. "Totals for 2013 and 2014 add up to much less than 100%."

In figures 5a-5d, some totals for years 2013 and 2014 add up to considerably less than 100%. This is a result of some responses being left off the chart because in this years' survey nobody gave those responses. In particular, the response "I don't vote for parties, I vote for candidates" was popular in previous years, but it was not mentioned in 2015.

The complete numbers for these four charts are presented below. Figures that were not included in the brief are presented in italics. For 2015, both unrounded and rounded figures are shown.

For Figure 5a: If the election was held today, which political party's candidate would you vote for? President
[TABLE="width: 604"]
[TR]
[TD][/TD]
[TD]

2012​

[/TD]
[TD]

2013​

[/TD]
[TD]

2014​

[/TD]
[TD="colspan: 2"]

2015​

[/TD]
[/TR]
[TR]
[TD]

Unrounded​

[/TD]
[TD]

Rounded​

[/TD]
[/TR]
[TR]
[TD] CCM[/TD]
[TD]

61%​

[/TD]
[TD]

47%​

[/TD]
[TD]

51%​

[/TD]
[TD]

65.8%​

[/TD]
[TD]

66%​

[/TD]
[/TR]
[TR]
[TD] Chadema[/TD]
[TD]

30%​

[/TD]
[TD]

30%​

[/TD]
[TD]

23%​

[/TD]
[TD]

21.5%​

[/TD]
[TD]

22%​

[/TD]
[/TR]
[TR]
[TD] CUF[/TD]
[TD]

4%​

[/TD]
[TD]

4%​

[/TD]
[TD]

4%​

[/TD]
[TD]

0.5%​

[/TD]
[TD]

1%​

[/TD]
[/TR]
[TR]
[TD] ACT-Wazalendo[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0.2%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] NCCR Mageuzi[/TD]
[TD]

0%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1%​

[/TD]
[TD]

0.2%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] Ukawa*[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

3.3%​

[/TD]
[TD]

3%​

[/TD]
[/TR]
[TR]
[TD] Other[/TD]
[TD]

1%​

[/TD]
[TD]

2%​

[/TD]
[TD]

0%​

[/TD]
[TD]

6.3%​

[/TD]
[TD]

6%​

[/TD]
[/TR]
[TR]
[TD] Don't know / no response[/TD]
[TD]

4%​

[/TD]
[TD]

0%​

[/TD]
[TD]

4%​

[/TD]
[TD]

2.2%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] I don't vote for parties but candidates[/TD]
[TD]

0%​

[/TD]
[TD]

15%​

[/TD]
[TD]

16%​

[/TD]
[TD]

0.0%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] None[/TD]
[TD]

0%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1%​

[/TD]
[TD]

0.0%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] Total[/TD]
[TD]

100%​

[/TD]
[TD]

100%​

[/TD]
[TD]

100%​

[/TD]
[TD]

100.0%​

[/TD]
[TD]

100%​

[/TD]
[/TR]
[/TABLE]

For Figure 5b: If the election was held today, which political party's candidate would you vote for? Member of Parliament
[TABLE="width: 604"]
[TR]
[TD][/TD]
[TD]

2012​

[/TD]
[TD]

2013​

[/TD]
[TD]

2014​

[/TD]
[TD="colspan: 2"]

2015​

[/TD]
[/TR]
[TR]
[TD]

Unrounded​

[/TD]
[TD]

Rounded​

[/TD]
[/TR]
[TR]
[TD] CCM[/TD]
[TD]

60%​

[/TD]
[TD]

44%​

[/TD]
[TD]

46%​

[/TD]
[TD]

60.4%​

[/TD]
[TD]

60%​

[/TD]
[/TR]
[TR]
[TD] Chadema[/TD]
[TD]

31%​

[/TD]
[TD]

31%​

[/TD]
[TD]

24%​

[/TD]
[TD]

24.1%​

[/TD]
[TD]

24%​

[/TD]
[/TR]
[TR]
[TD] CUF[/TD]
[TD]

4%​

[/TD]
[TD]

4%​

[/TD]
[TD]

4%​

[/TD]
[TD]

1.8%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] ACT-Wazalendo[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

1.4%​

[/TD]
[TD]

1%​

[/TD]
[/TR]
[TR]
[TD] NCCR Mageuzi[/TD]
[TD]

0%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1.1%​

[/TD]
[TD]

1%​

[/TD]
[/TR]
[TR]
[TD] Ukawa*[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

2.8%​

[/TD]
[TD]

3%​

[/TD]
[/TR]
[TR]
[TD] Other[/TD]
[TD]

0%​

[/TD]
[TD]

2%​

[/TD]
[TD]

1%​

[/TD]
[TD]

6.4%​

[/TD]
[TD]

6%​

[/TD]
[/TR]
[TR]
[TD] Don't know / no response[/TD]
[TD]

5%​

[/TD]
[TD]

0%​

[/TD]
[TD]

5%​

[/TD]
[TD]

2.0%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] I don't vote for parties but candidates[/TD]
[TD]

0%​

[/TD]
[TD]

17%​

[/TD]
[TD]

18%​

[/TD]
[TD]

0.0%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] None[/TD]
[TD]

0%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1%​

[/TD]
[TD]

0.0%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] Total[/TD]
[TD]

100%​

[/TD]
[TD]

100%​

[/TD]
[TD]

100%​

[/TD]
[TD]

100.0%​

[/TD]
[TD]

99%​

[/TD]
[/TR]
[/TABLE]


For Figure 5c: If the election was held today, which political party's candidate would you vote for? Councillor
[TABLE="width: 604"]
[TR]
[TD][/TD]
[TD]

2012​

[/TD]
[TD]

2013​

[/TD]
[TD]

2014​

[/TD]
[TD="colspan: 2"]

2015​

[/TD]
[/TR]
[TR]
[TD]

Unrounded​

[/TD]
[TD]

Rounded​

[/TD]
[/TR]
[TR]
[TD] CCM[/TD]
[TD]

61%​

[/TD]
[TD]

45%​

[/TD]
[TD]

47%​

[/TD]
[TD]

59.9%​

[/TD]
[TD]

60%​

[/TD]
[/TR]
[TR]
[TD] Chadema[/TD]
[TD]

29%​

[/TD]
[TD]

30%​

[/TD]
[TD]

23%​

[/TD]
[TD]

25.5%​

[/TD]
[TD]

26%​

[/TD]
[/TR]
[TR]
[TD] CUF[/TD]
[TD]

4%​

[/TD]
[TD]

4%​

[/TD]
[TD]

4%​

[/TD]
[TD]

2.5%​

[/TD]
[TD]

3%​

[/TD]
[/TR]
[TR]
[TD] ACT-Wazalendo[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0.6%​

[/TD]
[TD]

1%​

[/TD]
[/TR]
[TR]
[TD] NCCR Mageuzi[/TD]
[TD]

0%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1.0%​

[/TD]
[TD]

1%​

[/TD]
[/TR]
[TR]
[TD] Ukawa*[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

2.6%​

[/TD]
[TD]

3%​

[/TD]
[/TR]
[TR]
[TD] Other[/TD]
[TD]

1%​

[/TD]
[TD]

2%​

[/TD]
[TD]

1%​

[/TD]
[TD]

6.0%​

[/TD]
[TD]

6%​

[/TD]
[/TR]
[TR]
[TD] Don't know / no response[/TD]
[TD]

5%​

[/TD]
[TD]

0%​

[/TD]
[TD]

5%​

[/TD]
[TD]

1.9%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] I don't vote for parties but candidates[/TD]
[TD]

0%​

[/TD]
[TD]

17%​

[/TD]
[TD]

18%​

[/TD]
[TD]

0.0%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] None[/TD]
[TD]

0%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1%​

[/TD]
[TD]

0.0%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] Total[/TD]
[TD]

100%​

[/TD]
[TD]

100%​

[/TD]
[TD]

100%​

[/TD]
[TD]

100.0%​

[/TD]
[TD]

102%​

[/TD]
[/TR]
[/TABLE]


For Figure 5d: Which political party do you feel closest to, if any?
[TABLE="width: 604"]
[TR]
[TD][/TD]
[TD]

2012​

[/TD]
[TD]

2013​

[/TD]
[TD]

2014​

[/TD]
[TD="colspan: 2"]

2015​

[/TD]
[/TR]
[TR]
[TD]

Unrounded​

[/TD]
[TD]

Rounded​

[/TD]
[/TR]
[TR]
[TD] CCM[/TD]
[TD]

65%​

[/TD]
[TD]

54%​

[/TD]
[TD]

54%​

[/TD]
[TD]

61.9%​

[/TD]
[TD]

62%​

[/TD]
[/TR]
[TR]
[TD] Chadema[/TD]
[TD]

26%​

[/TD]
[TD]

32%​

[/TD]
[TD]

27%​

[/TD]
[TD]

25.0%​

[/TD]
[TD]

25%​

[/TD]
[/TR]
[TR]
[TD] CUF[/TD]
[TD]

3%​

[/TD]
[TD]

4%​

[/TD]
[TD]

4%​

[/TD]
[TD]

2.3%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] ACT-Wazalendo[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0.7%​

[/TD]
[TD]

1%​

[/TD]
[/TR]
[TR]
[TD] NCCR Mageuzi[/TD]
[TD]

0%​

[/TD]
[TD]

1%​

[/TD]
[TD]

1%​

[/TD]
[TD]

0.3%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] Ukawa*[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

0%​

[/TD]
[TD]

2.1%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] Other[/TD]
[TD]

2%​

[/TD]
[TD]

1%​

[/TD]
[TD]

2%​

[/TD]
[TD]

2.3%​

[/TD]
[TD]

2%​

[/TD]
[/TR]
[TR]
[TD] Don't know / no response[/TD]
[TD]

4%​

[/TD]
[TD]

0%​

[/TD]
[TD]

2%​

[/TD]
[TD]

5.3%​

[/TD]
[TD]

5%​

[/TD]
[/TR]
[TR]
[TD] I don't have a party affiliation[/TD]
[TD]

0%​

[/TD]
[TD]

8%​

[/TD]
[TD]

10%​

[/TD]
[TD]

0.0%​

[/TD]
[TD]

0%​

[/TD]
[/TR]
[TR]
[TD] Total[/TD]
[TD]

100%​

[/TD]
[TD]

100%​

[/TD]
[TD]

100%​

[/TD]
[TD]

100.0%​

[/TD]
[TD]

99%​

[/TD]
[/TR]
[/TABLE]


3. "A sample size of just 1,848 respondents is not sufficient."

Some have suggested that a sample size of 1,848 people is not sufficient to give a reliable answer. This suggestion is wrong. What matters most is how those people are selected: if they are selected at random, in a way that is representative of the whole of the country's voting age population, then even a much smaller sample can give useful findings.

In countries with much larger populations than Tanzania - such as the USA - opinion poll surveys are commonly done with a sample size of around 1000. The well-respected Afrobarometer survey has a sample size of 2,400 people in Tanzania.

They are still able to make statistically valid conclusions about the entire population's opinions. In contrast, if participants in a survey are self-selecting (such as with most online surveys) or if the sampling technique makes it impossible for large sections of the population to participate (also as with most online surveys), then even a very large sample size will not give statistically reliable results.

In this Sauti za Wananchi survey by Twaweza, respondents were randomly selected and they are representative of the whole country's voting age population. Therefore, for this sample size, we are 95% confident that the figures presented are an accurate representation of the whole population to within a margin of error of +/- 2.5%. This sample size, confidence level and margin of error are in line with global best practice for opinion poll surveys.

Source: Addressing common concerns raised about Twaweza's opinion poll survey

 

[House of Commons]

Spendi hata kuwaskia nie watu

 

[Steven Robert Masatu]

Kwanini wanalazisha tukubali maoni ya sample 1800 ilhali maoni ya watu lakitatu yalikataliwa?

Watujibu na hilo then tusonge mbele.

 

[mwinukai]

hakuna kitu hapa

 

[jogoo_dume]

Kwanini wanalazisha tukubali maoni ya sample 1800 ilhali maoni ya watu lakitatu yalikataliwa?

Watujibu na hilo then tusonge mbele.

Umejibiwa kitaratibu za tafiti bado unabisha, yaani lengo lenu ni ziwe upande wa Loassa tu basi. Habari ndo hiyo Magifuli mdogo mdogo anapiga pushap anainuka anatrot kuelekea ikulu, anapiga pushap anainuka anatrot anaelekea ikulu!
Acheni kutumia tafiti za eti NYOMI ile hatari.

 

[nolieonlytruth]

They had to use English ha...

 

[mzeewamakavu]

Twaweza kuleni pesa za wajinga utafiti wenu feki hautaisaidia CCM kwani rais hapatikani kwa utafiti Bali kwa kura

 

[jogoo_dume]

Kwanini wanalazisha tukubali maoni ya sample 1800 ilhali maoni ya watu lakitatu yalikataliwa?

Watujibu na hilo then tusonge mbele.

Sio lazima ukubali, wee kataa bhana, kubali hoyo ya lako tatu!

 

[Josorobert]

Kwanini wanalazisha tukubali maoni ya sample 1800 ilhali maoni ya watu lakitatu yalikataliwa?

Watujibu na hilo then tusonge mbele.

Tatizo lako ni sample ndogo? Na leo kuhusu SNOVATE sample ikoje

 

[msemakweli]

Go home TWAWEZA.....and get hit by a truck on your way there.....nobody cares about you!

 

[The Palm Tree]

You don't need to clarify anything because we know your research was not scientific at all and does not project the reality!

 

[Mtu_Mzima]

Explain this picture also

 

[mumburya]

mbona zingine hamtoagi live hii ya juzi mlipata wapi mchuzi?

 

[Kasongo]

Explain this picture also

Haaaaa haaaa

 

[Donyongijape]

Vipi kuhusu Timing ya huo utafiti? Kwa maana tumeambiwa umefanyika hata kabla kampeni kuanza.

Na vipi kuhusu suala la kuwapa simu na chaja watu unawahoji?. Why do you think this is proper methodology?. Hii siyo Hongo?. Na je unaitofautishaje na hongo?.

Utafiti uliokuwa unasema kuwa waliosoma na wasiosoma wanawaona hivi wagombea, hao wasiosoma hizo gadgets mlizowapa hazikuwainfluence?. Hao waliosoma ni watu wa level gani?.

TWAWEZA Naombeni Majibu tafadhal

 

[Masonjo]

Explain this picture also

Kweli haupo informed, hiyo ni picha ya mwezi wa 7 mwanzoni wakati wa mdahalo wa wagombea urais waliochukua fomu CCM, waliohudhuria Mwigulu na Kigwangala aliyevaa suti nyeusi na moderator alikuwa huyo dada Maria Sarungi,mdahalo huo ulirushwa live hapa JF pia.

Kuishi kwa uongo hakutawasaidia,ndio tatizo la UKAWA kutunga uongo na kujiaminisha kwa uongo,bahati mbaya uongo wenu wa mitandaoni hauwezi kuwapa ushindi,tafiti hizi ni ishara ya kinachokuja tarehe 25/10,jiandaeni kisaikolojia.

 

[Masonjo]

Vipi kuhusu Timing ya huo utafiti? Kwa maana tumeambiwa umefanyika hata kabla kampeni kuanza.

Na vipi kuhusu suala la kuwapa simu na chaja watu unawahoji?. Why do you think this is proper methodology?. Hii siyo Hongo?. Na je unaitofautishaje na hongo?.

Utafiti uliokuwa unasema kuwa waliosoma na wasiosoma wanawaona hivi wagombea, hao wasiosoma hizo gadgets mlizowapa hazikuwainfluence?. Hao waliosoma ni watu wa level gani?.

TWAWEZA Naombeni Majibu tafadhal

Majibu yote yapo kwenye report yao,usiwe mvivu wa kusoma.


Utafiti wa TWAWEZA umefanywa mpaka tarehe 8/09, kampeni zimeanza tarehe 23/08, hivyo usidanganywe kuwa kampeni hazikuwa zimeanza.


Leo umetoka utafiti wa SYNOVATE ambao wenyewe umefanyika tarehe 4/9 mpaka tarehe 22/09, matokeo yake ni bado Magufuli 62% na Lowassa 31%.

 

[aiai654]

Wanajitetea nini? Soon wataumbuka big time

 

[hopaje]

Hamuwezi

 

[Bavaria]

Twaweza ni vimeo sana. Watoe ripoti original ripoti.